diff --git a/.php_cs b/.php_cs
index dd317cd..5184eaf 100644
--- a/.php_cs
+++ b/.php_cs
@@ -1,20 +1,45 @@
 <?php
 
-return Symfony\CS\Config\Config::create()
-    ->setUsingCache(true)
-    ->level(Symfony\CS\FixerInterface::SYMFONY_LEVEL)
-    // use default SYMFONY_LEVEL and extra fixers:
-    ->fixers(array(
-        'concat_with_spaces',
-        'ordered_use',
-        'phpdoc_order',
-        'strict',
-        'strict_param',
-        'short_array_syntax',
-    ))
-    ->finder(
-        Symfony\CS\Finder::create()
+return PhpCsFixer\Config::create()
+    ->setRiskyAllowed(true)
+    ->setRules([
+        '@Symfony' => true,
+        '@Symfony:risky' => true,
+        'array_syntax' => [
+            'syntax' => 'short'
+        ],
+        'combine_consecutive_unsets' => true,
+        'heredoc_to_nowdoc' => true,
+        'no_extra_consecutive_blank_lines' => [
+        'break',
+            'continue',
+            'extra',
+            'return',
+            'throw',
+            'use',
+            'parenthesis_brace_block',
+            'square_brace_block',
+            'curly_brace_block'
+        ],
+        'no_unreachable_default_argument_value' => true,
+        'no_useless_else' => true,
+        'no_useless_return' => true,
+        'ordered_class_elements' => true,
+        'ordered_imports' => true,
+        'php_unit_strict' => true,
+        'phpdoc_order' => true,
+        // 'psr4' => true,
+        'strict_comparison' => true,
+        'strict_param' => true,
+        'concat_space' => [
+            'spacing' => 'one'
+        ],
+    ])
+    ->setFinder(
+        PhpCsFixer\Finder::create()
+            ->exclude([
+                'vendor',
+            ])
             ->in(__DIR__)
-            ->exclude(array('vendor'))
     )
 ;
diff --git a/.travis.yml b/.travis.yml
index 491012a..b668bcf 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,21 +1,20 @@
 language: php
 
 php:
-    - 5.5
     - 5.6
     - 7.0
     - 7.1
+    - 7.2
+    - 7.3
     - nightly
-    - hhvm
 
 # run build against nightly but allow them to fail
 matrix:
     fast_finish: true
     include:
-        - php: 7.0
+        - php: 7.2
           env: CS_FIXER=run
     allow_failures:
-        - php: hhvm
         - php: nightly
 
 # faster builds on new travis setup not using sudo
@@ -34,7 +33,7 @@ before_script:
     - composer install --prefer-dist --no-interaction
 
 script:
-    - phpunit --coverage-clover=coverage.clover
+    - ./vendor/bin/simple-phpunit -v --coverage-clover=coverage.clover
     - if [ "$CS_FIXER" = "run" ]; then php vendor/bin/php-cs-fixer fix --verbose --dry-run ; fi;
 
 after_script:
diff --git a/README.md b/README.md
index d7fcbff..1260f8b 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@ Uses [Imgur API v3](https://api.imgur.com/).
 * Branch [2.x](https://github.com/j0k3r/php-imgur-api-client/tree/2.x) use Guzzle 5
 * Branch [3.x](https://github.com/j0k3r/php-imgur-api-client/tree/3.x) use Guzzle 6
 
-All actives branches required PHP >= 5.5
+All actives branches required PHP >= 5.6
 
 ## Composer
 
@@ -52,7 +52,7 @@ if (isset($_SESSION['token'])) {
     $client->setAccessToken($_SESSION['token']);
 
     if ($client->checkAccessTokenExpired()) {
-          $client->refreshToken();
+        $client->refreshToken();
     }
 } elseif (isset($_GET['code'])) {
     $client->requestAccessToken($_GET['code']);
diff --git a/composer.json b/composer.json
index 5dd2197..10bb460 100644
--- a/composer.json
+++ b/composer.json
@@ -34,12 +34,13 @@
         }
     },
     "require": {
-        "php": ">=5.5.0",
+        "php": ">=5.6.0",
         "ext-curl": "*",
         "guzzlehttp/guzzle": "^5.3.1"
     },
     "require-dev": {
-        "friendsofphp/php-cs-fixer": "~1.9"
+        "friendsofphp/php-cs-fixer": "~2.11",
+        "symfony/phpunit-bridge": "^4.0"
     },
     "extra": {
         "branch-alias": {
diff --git a/lib/Imgur/Api/AbstractApi.php b/lib/Imgur/Api/AbstractApi.php
index 7b5d376..57a6b3b 100644
--- a/lib/Imgur/Api/AbstractApi.php
+++ b/lib/Imgur/Api/AbstractApi.php
@@ -98,20 +98,6 @@ public function delete($url, $parameters = [])
         return $httpClient->parseResponse($response);
     }
 
-    /**
-     * Global method to validate an argument.
-     *
-     * @param string $type           The required parameter (used for the error message)
-     * @param string $input          Input value
-     * @param array  $possibleValues Possible values for this argument
-     */
-    private function validateArgument($type, $input, $possibleValues)
-    {
-        if (!in_array($input, $possibleValues, true)) {
-            throw new InvalidArgumentException($type . ' parameter "' . $input . '" is wrong. Possible values are: ' . implode(', ', $possibleValues));
-        }
-    }
-
     /**
      * Validate "sort" parameter and throw an exception if it's a bad value.
      *
@@ -144,4 +130,18 @@ protected function validateVoteArgument($vote, $possibleValues)
     {
         $this->validateArgument('Vote', $vote, $possibleValues);
     }
+
+    /**
+     * Global method to validate an argument.
+     *
+     * @param string $type           The required parameter (used for the error message)
+     * @param string $input          Input value
+     * @param array  $possibleValues Possible values for this argument
+     */
+    private function validateArgument($type, $input, $possibleValues)
+    {
+        if (!\in_array($input, $possibleValues, true)) {
+            throw new InvalidArgumentException($type . ' parameter "' . $input . '" is wrong. Possible values are: ' . implode(', ', $possibleValues));
+        }
+    }
 }
diff --git a/lib/Imgur/Api/Account.php b/lib/Imgur/Api/Account.php
index 074c56c..33656a4 100644
--- a/lib/Imgur/Api/Account.php
+++ b/lib/Imgur/Api/Account.php
@@ -5,7 +5,7 @@
 /**
  * CRUD for Accounts.
  *
- * @link https://api.imgur.com/endpoints/account
+ * @see https://api.imgur.com/endpoints/account
  *
  * @author Adrian Ghiuta <adrian.ghiuta@gmail.com>
  */
@@ -16,7 +16,7 @@ class Account extends AbstractApi
      *
      * @param string $username
      *
-     * @link https://api.imgur.com/endpoints/account#account
+     * @see https://api.imgur.com/endpoints/account#account
      *
      * @return array Account (@see https://api.imgur.com/models/account)
      */
@@ -45,7 +45,7 @@ public function deleteAccount($username)
      * @param int    $page
      * @param string $sort     'oldest', or 'newest'. Defaults to 'newest'
      *
-     * @link https://api.imgur.com/endpoints/account#account-gallery-favorites
+     * @see https://api.imgur.com/endpoints/account#account-gallery-favorites
      *
      * @return array Gallery Image (@see https://api.imgur.com/models/gallery_image) OR Gallery Album (@see https://api.imgur.com/models/gallery_album)
      */
@@ -61,7 +61,7 @@ public function galleryFavorites($username = 'me', $page = 0, $sort = 'newest')
      *
      * @param string $username
      *
-     * @link https://api.imgur.com/endpoints/account#account-favorites
+     * @see https://api.imgur.com/endpoints/account#account-favorites
      *
      * @return array Gallery Image (@see https://api.imgur.com/models/gallery_image) OR Gallery Album (@see https://api.imgur.com/models/gallery_album)
      */
@@ -76,7 +76,7 @@ public function favorites($username = 'me')
      * @param string $username
      * @param int    $page
      *
-     * @link https://api.imgur.com/endpoints/account#account-submissions
+     * @see https://api.imgur.com/endpoints/account#account-submissions
      *
      * @return array Gallery Image (@see https://api.imgur.com/models/gallery_image) OR Gallery Album (@see https://api.imgur.com/models/gallery_album)
      */
@@ -90,7 +90,7 @@ public function submissions($username = 'me', $page = 0)
      *
      * @param string $username
      *
-     * @link https://api.imgur.com/endpoints/account#account-settings
+     * @see https://api.imgur.com/endpoints/account#account-settings
      *
      * @return array Account Settings (@see https://api.imgur.com/models/account_settings)
      */
@@ -104,7 +104,7 @@ public function settings($username = 'me')
      *
      * @param array $parameters
      *
-     * @link https://api.imgur.com/endpoints/account#update-settings
+     * @see https://api.imgur.com/endpoints/account#update-settings
      *
      * @return bool
      */
@@ -131,7 +131,7 @@ public function accountStats($username = 'me')
      *
      * @param string $username
      *
-     * @link https://api.imgur.com/endpoints/account#account-profile
+     * @see https://api.imgur.com/endpoints/account#account-profile
      *
      * @return array Gallery Profile (@see https://api.imgur.com/models/gallery_profile)
      */
@@ -145,7 +145,7 @@ public function accountGalleryProfile($username = 'me')
      *
      * @param string $username
      *
-     * @link https://api.imgur.com/endpoints/account#verify-email
+     * @see https://api.imgur.com/endpoints/account#verify-email
      *
      * @return bool
      */
@@ -159,7 +159,7 @@ public function verifyUsersEmail($username = 'me')
      *
      * @param string $username
      *
-     * @link https://api.imgur.com/endpoints/account#send-verify-email
+     * @see https://api.imgur.com/endpoints/account#send-verify-email
      *
      * @return bool
      */
@@ -174,7 +174,7 @@ public function sendVerificationEmail($username = 'me')
      * @param string $username
      * @param int    $page
      *
-     * @link https://api.imgur.com/endpoints/account#albums
+     * @see https://api.imgur.com/endpoints/account#albums
      *
      * @return array Array of Album (@see https://api.imgur.com/models/album)
      */
@@ -190,7 +190,7 @@ public function albums($username = 'me', $page = 0)
      * @param string $username
      * @param string $albumId
      *
-     * @link https://api.imgur.com/endpoints/account#album
+     * @see https://api.imgur.com/endpoints/account#album
      *
      * @return array Album (@see https://api.imgur.com/models/album)
      */
@@ -205,7 +205,7 @@ public function album($albumId, $username = 'me')
      * @param string $username
      * @param int    $page
      *
-     * @link https://api.imgur.com/endpoints/account#album-ids
+     * @see https://api.imgur.com/endpoints/account#album-ids
      *
      * @return array<int>
      */
@@ -219,7 +219,7 @@ public function albumIds($username = 'me', $page = 0)
      *
      * @param string $username
      *
-     * @link https://api.imgur.com/endpoints/account#album-count
+     * @see https://api.imgur.com/endpoints/account#album-count
      *
      * @return int
      */
@@ -234,7 +234,7 @@ public function albumCount($username = 'me')
      * @param string $username
      * @param string $albumId
      *
-     * @link https://api.imgur.com/endpoints/account#album-delete
+     * @see https://api.imgur.com/endpoints/account#album-delete
      *
      * @return bool
      */
@@ -250,7 +250,7 @@ public function albumDelete($albumId, $username = 'me')
      * @param int    $page
      * @param string $sort     'best', 'worst', 'oldest', or 'newest'. Defaults to 'newest'
      *
-     * @link https://api.imgur.com/endpoints/account#comments
+     * @see https://api.imgur.com/endpoints/account#comments
      *
      * @return array Array of Comment (@see https://api.imgur.com/models/comment)
      */
@@ -268,7 +268,7 @@ public function comments($username = 'me', $page = 0, $sort = 'newest')
      * @param string $commentId
      * @param string $username
      *
-     * @link https://api.imgur.com/endpoints/account#comment
+     * @see https://api.imgur.com/endpoints/account#comment
      *
      * @return array Comment (@see https://api.imgur.com/models/comment)
      */
@@ -284,7 +284,7 @@ public function comment($commentId, $username = 'me')
      * @param int    $page
      * @param string $sort     'best', 'worst', 'oldest', or 'newest'. Defaults to 'newest'
      *
-     * @link https://api.imgur.com/endpoints/account#comment-ids
+     * @see https://api.imgur.com/endpoints/account#comment-ids
      *
      * @return array<int>
      */
@@ -300,7 +300,7 @@ public function commentIds($username = 'me', $page = 0, $sort = 'newest')
      *
      * @param string $username
      *
-     * @link https://api.imgur.com/endpoints/account#comment-count
+     * @see https://api.imgur.com/endpoints/account#comment-count
      *
      * @return int
      */
@@ -315,7 +315,7 @@ public function commentCount($username = 'me')
      * @param string $commentId
      * @param string $username
      *
-     * @link https://api.imgur.com/endpoints/account#comment-delete
+     * @see https://api.imgur.com/endpoints/account#comment-delete
      *
      * @return bool
      */
@@ -331,7 +331,7 @@ public function commentDelete($commentId, $username = 'me')
      * @param string $username
      * @param int    $page
      *
-     * @link https://api.imgur.com/endpoints/account#images
+     * @see https://api.imgur.com/endpoints/account#images
      *
      * @return array Array of Image (@see https://api.imgur.com/models/image)
      */
@@ -347,7 +347,7 @@ public function images($username = 'me', $page = 0)
      * @param string $imageId
      * @param string $username
      *
-     * @link https://api.imgur.com/endpoints/account#image
+     * @see https://api.imgur.com/endpoints/account#image
      *
      * @return array Image (@see https://api.imgur.com/models/image)
      */
@@ -362,7 +362,7 @@ public function image($imageId, $username = 'me')
      * @param string $username
      * @param int    $page
      *
-     * @link https://api.imgur.com/endpoints/account#image-ids
+     * @see https://api.imgur.com/endpoints/account#image-ids
      *
      * @return array<int>
      */
@@ -376,7 +376,7 @@ public function imageIds($username = 'me', $page = 0)
      *
      * @param string $username
      *
-     * @link https://api.imgur.com/endpoints/account#image-count
+     * @see https://api.imgur.com/endpoints/account#image-count
      *
      * @return int
      */
@@ -391,7 +391,7 @@ public function imageCount($username = 'me')
      * @param string $deleteHash
      * @param string $username
      *
-     * @link https://api.imgur.com/endpoints/account#image-delete
+     * @see https://api.imgur.com/endpoints/account#image-delete
      *
      * @return bool
      */
@@ -406,7 +406,7 @@ public function imageDelete($deleteHash, $username = 'me')
      * @param string $username
      * @param bool   $onlyNew
      *
-     * @link https://api.imgur.com/endpoints/account#replies
+     * @see https://api.imgur.com/endpoints/account#replies
      *
      * @return array Array of Notification (@see https://api.imgur.com/models/notification)
      */
diff --git a/lib/Imgur/Api/Album.php b/lib/Imgur/Api/Album.php
index 1e4336b..a30ceed 100644
--- a/lib/Imgur/Api/Album.php
+++ b/lib/Imgur/Api/Album.php
@@ -5,7 +5,7 @@
 /**
  * CRUD for Albums.
  *
- * @link https://api.imgur.com/endpoints/album
+ * @see https://api.imgur.com/endpoints/album
  *
  * @author Adrian Ghiuta <adrian.ghiuta@gmail.com>
  */
@@ -16,7 +16,7 @@ class Album extends AbstractApi
      *
      * @param string $albumId
      *
-     * @link https://api.imgur.com/endpoints/album#album
+     * @see https://api.imgur.com/endpoints/album#album
      *
      * @return array Album (@see https://api.imgur.com/models/album)
      */
@@ -30,7 +30,7 @@ public function album($albumId)
      *
      * @param string $albumId
      *
-     * @link https://api.imgur.com/endpoints/album#album-images
+     * @see https://api.imgur.com/endpoints/album#album-images
      *
      * @return array Array of Image (@see https://api.imgur.com/models/image)
      */
@@ -45,7 +45,7 @@ public function albumImages($albumId)
      * @param string $albumId
      * @param string $imageId
      *
-     * @link https://api.imgur.com/endpoints/album#album-image
+     * @see https://api.imgur.com/endpoints/album#album-image
      *
      * @return array Image (@see https://api.imgur.com/models/image)
      */
@@ -62,7 +62,7 @@ public function albumImage($albumId, $imageId)
      *
      * @param array $data
      *
-     * @link https://api.imgur.com/endpoints/album#album-upload
+     * @see https://api.imgur.com/endpoints/album#album-upload
      *
      * @return bool
      */
@@ -78,7 +78,7 @@ public function create($data)
      * @param string $deletehashOrAlbumId
      * @param array  $data
      *
-     * @link https://api.imgur.com/endpoints/album#album-update
+     * @see https://api.imgur.com/endpoints/album#album-update
      *
      * @return bool
      */
@@ -94,7 +94,7 @@ public function update($deletehashOrAlbumId, $data)
      *
      * @param string $deletehashOrAlbumId
      *
-     * @link https://api.imgur.com/endpoints/album#album-delete
+     * @see https://api.imgur.com/endpoints/album#album-delete
      *
      * @return bool
      */
@@ -108,7 +108,7 @@ public function deleteAlbum($deletehashOrAlbumId)
      *
      * @param string $albumId
      *
-     * @link https://api.imgur.com/endpoints/album#album-favorite
+     * @see https://api.imgur.com/endpoints/album#album-favorite
      *
      * @return bool
      */
@@ -124,7 +124,7 @@ public function favoriteAlbum($albumId)
      * @param string $albumId
      * @param array  $imageIds
      *
-     * @link https://api.imgur.com/endpoints/album#album-set-to
+     * @see https://api.imgur.com/endpoints/album#album-set-to
      *
      * @return bool
      */
@@ -140,7 +140,7 @@ public function setAlbumImages($albumId, array $imageIds)
      * @param string $albumId
      * @param array  $imageIds
      *
-     * @link https://api.imgur.com/endpoints/album#album-add-to
+     * @see https://api.imgur.com/endpoints/album#album-add-to
      *
      * @return bool
      */
@@ -156,7 +156,7 @@ public function addImages($albumId, array $imageIds)
      * @param string $deletehashOrAlbumId
      * @param array  $imageIds
      *
-     * @link https://api.imgur.com/endpoints/album#album-remove-from
+     * @see https://api.imgur.com/endpoints/album#album-remove-from
      *
      * @return bool
      */
diff --git a/lib/Imgur/Api/AlbumOrImage.php b/lib/Imgur/Api/AlbumOrImage.php
index c10830e..64fdf79 100644
--- a/lib/Imgur/Api/AlbumOrImage.php
+++ b/lib/Imgur/Api/AlbumOrImage.php
@@ -24,7 +24,7 @@ public function find($imageIdOrAlbumId)
         try {
             return $this->get('image/' . $imageIdOrAlbumId);
         } catch (ExceptionInterface $e) {
-            if ($e->getCode() !== 404) {
+            if (404 !== $e->getCode()) {
                 throw $e;
             }
         }
@@ -32,7 +32,7 @@ public function find($imageIdOrAlbumId)
         try {
             return $this->get('album/' . $imageIdOrAlbumId);
         } catch (ExceptionInterface $e) {
-            if ($e->getCode() !== 404) {
+            if (404 !== $e->getCode()) {
                 throw $e;
             }
         }
diff --git a/lib/Imgur/Api/Comment.php b/lib/Imgur/Api/Comment.php
index 4741f10..20a5bcb 100644
--- a/lib/Imgur/Api/Comment.php
+++ b/lib/Imgur/Api/Comment.php
@@ -7,7 +7,7 @@
 /**
  * CRUD for Comment.
  *
- * @link https://api.imgur.com/endpoints/comment
+ * @see https://api.imgur.com/endpoints/comment
  *
  * @author Adrian Ghiuta <adrian.ghiuta@gmail.com>
  */
@@ -18,7 +18,7 @@ class Comment extends AbstractApi
      *
      * @param string $commentId
      *
-     * @link https://api.imgur.com/endpoints/comment#comment
+     * @see https://api.imgur.com/endpoints/comment#comment
      *
      * @return array Comment (@see https://api.imgur.com/endpoints/gallery#gallery-comments)
      */
@@ -32,7 +32,7 @@ public function comment($commentId)
      *
      * @param array $data
      *
-     * @link https://api.imgur.com/endpoints/comment#comment-create
+     * @see https://api.imgur.com/endpoints/comment#comment-create
      *
      * @return bool
      */
@@ -50,7 +50,7 @@ public function create($data)
      *
      * @param string $commentId
      *
-     * @link https://api.imgur.com/endpoints/comment#comment-delete
+     * @see https://api.imgur.com/endpoints/comment#comment-delete
      *
      * @return bool
      */
@@ -64,7 +64,7 @@ public function deleteComment($commentId)
      *
      * @param string $commentId
      *
-     * @link https://api.imgur.com/endpoints/comment#comment-replies
+     * @see https://api.imgur.com/endpoints/comment#comment-replies
      *
      * @return array Comment (@see https://api.imgur.com/endpoints/gallery#gallery-comments)
      */
@@ -79,7 +79,7 @@ public function replies($commentId)
      * @param string $commentId
      * @param array  $data
      *
-     * @link https://api.imgur.com/endpoints/comment#comment-reply-create
+     * @see https://api.imgur.com/endpoints/comment#comment-reply-create
      *
      * @return bool
      */
@@ -98,7 +98,7 @@ public function createReply($commentId, $data)
      * @param string $commentId
      * @param string $vote
      *
-     * @link https://api.imgur.com/endpoints/comment#comment-vote
+     * @see https://api.imgur.com/endpoints/comment#comment-vote
      *
      * @return bool
      */
@@ -114,7 +114,7 @@ public function vote($commentId, $vote)
      *
      * @param string $commentId
      *
-     * @link https://api.imgur.com/endpoints/comment#comment-report
+     * @see https://api.imgur.com/endpoints/comment#comment-report
      *
      * @return bool
      */
diff --git a/lib/Imgur/Api/Conversation.php b/lib/Imgur/Api/Conversation.php
index ba85deb..90b3327 100644
--- a/lib/Imgur/Api/Conversation.php
+++ b/lib/Imgur/Api/Conversation.php
@@ -7,7 +7,7 @@
 /**
  * CRUD for Conversations.
  *
- * @link https://api.imgur.com/endpoints/conversation
+ * @see https://api.imgur.com/endpoints/conversation
  *
  * @author Adrian Ghiuta <adrian.ghiuta@gmail.com>
  */
@@ -16,7 +16,7 @@ class Conversation extends AbstractApi
     /**
      * Get list of all conversations for the logged in user.
      *
-     * @link https://api.imgur.com/endpoints/conversation#conversation-list
+     * @see https://api.imgur.com/endpoints/conversation#conversation-list
      *
      * @return array Array of Conversation (@see https://api.imgur.com/models/conversation)
      */
@@ -30,7 +30,7 @@ public function conversations()
      *
      * @param string $conversationId
      *
-     * @link https://api.imgur.com/endpoints/conversation#conversation
+     * @see https://api.imgur.com/endpoints/conversation#conversation
      *
      * @return array Conversation (@see https://api.imgur.com/models/conversation)
      */
@@ -45,7 +45,7 @@ public function conversation($conversationId)
      *
      * @param array $data
      *
-     * @link https://api.imgur.com/endpoints/conversation#message-create
+     * @see https://api.imgur.com/endpoints/conversation#message-create
      *
      * @return bool
      */
@@ -63,7 +63,7 @@ public function messageCreate($data)
      *
      * @param string $conversationId
      *
-     * @link https://api.imgur.com/endpoints/conversation#message-delete
+     * @see https://api.imgur.com/endpoints/conversation#message-delete
      *
      * @return bool
      */
@@ -77,7 +77,7 @@ public function conversationDelete($conversationId)
      *
      * @param string $username
      *
-     * @link https://api.imgur.com/endpoints/conversation#message-report
+     * @see https://api.imgur.com/endpoints/conversation#message-report
      *
      * @return bool
      */
@@ -91,7 +91,7 @@ public function reportSender($username)
      *
      * @param string $username
      *
-     * @link https://api.imgur.com/endpoints/conversation#message-block
+     * @see https://api.imgur.com/endpoints/conversation#message-block
      *
      * @return bool
      */
diff --git a/lib/Imgur/Api/CustomGallery.php b/lib/Imgur/Api/CustomGallery.php
index c9aa45c..f20a92d 100644
--- a/lib/Imgur/Api/CustomGallery.php
+++ b/lib/Imgur/Api/CustomGallery.php
@@ -5,7 +5,7 @@
 /**
  * CRUD for CustomGallery.
  *
- * @link https://api.imgur.com/endpoints/custom_gallery
+ * @see https://api.imgur.com/endpoints/custom_gallery
  */
 class CustomGallery extends AbstractApi
 {
@@ -16,7 +16,7 @@ class CustomGallery extends AbstractApi
      * @param int    $page
      * @param string $window (day | week | month | year | all)
      *
-     * @link https://api.imgur.com/endpoints/custom_gallery#custom-gallery
+     * @see https://api.imgur.com/endpoints/custom_gallery#custom-gallery
      *
      * @return array Custom Gallery (@see https://api.imgur.com/models/custom_gallery)
      */
@@ -35,7 +35,7 @@ public function customGallery($sort = 'viral', $page = 0, $window = 'week')
      * @param int    $page
      * @param string $window (day | week | month | year | all)
      *
-     * @link https://api.imgur.com/endpoints/custom_gallery#filtered-out-gallery
+     * @see https://api.imgur.com/endpoints/custom_gallery#filtered-out-gallery
      *
      * @return array Custom Gallery (@see https://api.imgur.com/models/custom_gallery)
      */
@@ -52,7 +52,7 @@ public function filtered($sort = 'viral', $page = 0, $window = 'week')
      *
      * @param string $imageId The ID for the gallery item
      *
-     * @link https://api.imgur.com/endpoints/custom_gallery#custom-gallery-image
+     * @see https://api.imgur.com/endpoints/custom_gallery#custom-gallery-image
      *
      * @return array Gallery Image (@see https://api.imgur.com/models/gallery_image) OR Gallery Album (@see https://api.imgur.com/models/gallery_album)
      */
@@ -66,7 +66,7 @@ public function image($imageId)
      *
      * @param array $tags
      *
-     * @link https://api.imgur.com/endpoints/custom_gallery#custom-gallery-add
+     * @see https://api.imgur.com/endpoints/custom_gallery#custom-gallery-add
      *
      * @return bool
      */
@@ -80,7 +80,7 @@ public function addTags(array $tags)
      *
      * @param array $tags
      *
-     * @link https://api.imgur.com/endpoints/custom_gallery#custom-gallery-remove
+     * @see https://api.imgur.com/endpoints/custom_gallery#custom-gallery-remove
      *
      * @return bool
      */
@@ -94,7 +94,7 @@ public function removeTags(array $tags)
      *
      * @param string $tag
      *
-     * @link https://api.imgur.com/endpoints/custom_gallery#filtered-out-block
+     * @see https://api.imgur.com/endpoints/custom_gallery#filtered-out-block
      *
      * @return bool
      */
@@ -108,7 +108,7 @@ public function blockTag($tag)
      *
      * @param string $tag
      *
-     * @link https://api.imgur.com/endpoints/custom_gallery#filtered-out-unblock
+     * @see https://api.imgur.com/endpoints/custom_gallery#filtered-out-unblock
      *
      * @return bool
      */
diff --git a/lib/Imgur/Api/Gallery.php b/lib/Imgur/Api/Gallery.php
index 0fd84a7..dd0a999 100644
--- a/lib/Imgur/Api/Gallery.php
+++ b/lib/Imgur/Api/Gallery.php
@@ -8,7 +8,7 @@
 /**
  * CRUD for Gallery.
  *
- * @link https://api.imgur.com/endpoints/gallery
+ * @see https://api.imgur.com/endpoints/gallery
  *
  * @author Adrian Ghiuta <adrian.ghiuta@gmail.com>
  */
@@ -23,7 +23,7 @@ class Gallery extends AbstractApi
      * @param string $window    (day | week | month | year | all)
      * @param bool   $showViral
      *
-     * @link https://api.imgur.com/endpoints/gallery#gallery
+     * @see https://api.imgur.com/endpoints/gallery#gallery
      *
      * @return array Gallery Image (@see https://api.imgur.com/models/gallery_image) OR Gallery Album (@see https://api.imgur.com/models/gallery_album)
      */
@@ -33,7 +33,7 @@ public function gallery($section = 'hot', $sort = 'viral', $page = 0, $window =
         $this->validateWindowArgument($window, ['day', 'week', 'month', 'year', 'all']);
 
         $sectionValues = ['hot', 'top', 'user'];
-        if (!in_array($section, $sectionValues, true)) {
+        if (!\in_array($section, $sectionValues, true)) {
             throw new InvalidArgumentException('Section parameter "' . $section . '" is wrong. Possible values are: ' . implode(', ', $sectionValues));
         }
 
@@ -49,7 +49,7 @@ public function gallery($section = 'hot', $sort = 'viral', $page = 0, $window =
      * @param int    $page
      * @param string $window (day | week | month | year | all)
      *
-     * @link https://api.imgur.com/endpoints/gallery#meme-subgallery
+     * @see https://api.imgur.com/endpoints/gallery#meme-subgallery
      *
      * @return array Gallery Image (@see https://api.imgur.com/models/gallery_image) OR Gallery Album (@see https://api.imgur.com/models/gallery_album)
      */
@@ -67,7 +67,7 @@ public function memesSubgallery($sort = 'viral', $page = 0, $window = 'day')
      *
      * @param string $imageId
      *
-     * @link https://api.imgur.com/endpoints/gallery#meme-subgallery-image
+     * @see https://api.imgur.com/endpoints/gallery#meme-subgallery-image
      *
      * @return array Gallery Image (@see https://api.imgur.com/models/gallery_image)
      */
@@ -84,7 +84,7 @@ public function memeSubgalleryImage($imageId)
      * @param int    $page
      * @param string $window    (day | week | month | year | all)
      *
-     * @link https://api.imgur.com/endpoints/gallery#subreddit
+     * @see https://api.imgur.com/endpoints/gallery#subreddit
      *
      * @return array Gallery Image (@see https://api.imgur.com/models/gallery_image)
      */
@@ -102,7 +102,7 @@ public function subredditGalleries($subreddit, $sort = 'time', $page = 0, $windo
      * @param string $subreddit (e.g pics - A valid sub-reddit name)
      * @param string $imageId
      *
-     * @link https://api.imgur.com/endpoints/gallery#subreddit-image
+     * @see https://api.imgur.com/endpoints/gallery#subreddit-image
      *
      * @return array Gallery Image (@see https://api.imgur.com/models/gallery_image)
      */
@@ -119,7 +119,7 @@ public function subredditImage($subreddit, $imageId)
      * @param int    $page
      * @param string $window (day | week | month | year | all)
      *
-     * @link https://api.imgur.com/endpoints/gallery#gallery-tag
+     * @see https://api.imgur.com/endpoints/gallery#gallery-tag
      *
      * @return array Tag (@see https://api.imgur.com/models/tag)
      */
@@ -137,7 +137,7 @@ public function galleryTag($name, $sort = 'viral', $page = 0, $window = 'week')
      * @param string $name    The name of the tag
      * @param string $imageId The ID for the image
      *
-     * @link https://api.imgur.com/endpoints/gallery#gallery-tag-image
+     * @see https://api.imgur.com/endpoints/gallery#gallery-tag-image
      *
      * @return array Gallery Image (@see https://api.imgur.com/models/gallery_image)
      */
@@ -151,7 +151,7 @@ public function galleryTagImage($name, $imageId)
      *
      * @param string $imageOrAlbumId ID of the gallery item
      *
-     * @link https://api.imgur.com/endpoints/gallery#gallery-item-tags
+     * @see https://api.imgur.com/endpoints/gallery#gallery-item-tags
      *
      * @return array of Tag Votes (@see https://api.imgur.com/models/tag_vote)
      */
@@ -167,7 +167,7 @@ public function galleryItemTags($imageOrAlbumId)
      * @param string $name Name of the tag (implicitly created, if doesn't exist)
      * @param string $vote 'up' or 'down'
      *
-     * @link https://api.imgur.com/endpoints/gallery#gallery-tag-vote
+     * @see https://api.imgur.com/endpoints/gallery#gallery-tag-vote
      *
      * @return bool
      */
@@ -187,7 +187,7 @@ public function galleryVoteTag($id, $name, $vote)
      * @param string $sort  (time | viral | top)
      * @param int    $page
      *
-     * @link https://api.imgur.com/endpoints/gallery#gallery-search
+     * @see https://api.imgur.com/endpoints/gallery#gallery-search
      *
      * @return array Gallery Image (@see https://api.imgur.com/models/gallery_image) OR Gallery Album (@see https://api.imgur.com/models/gallery_album)
      */
@@ -203,7 +203,7 @@ public function search($query, $sort = 'time', $page = 0)
      *
      * @param int $page
      *
-     * @link https://api.imgur.com/endpoints/gallery#gallery-random
+     * @see https://api.imgur.com/endpoints/gallery#gallery-random
      *
      * @return array Gallery Image (@see https://api.imgur.com/models/gallery_image) OR Gallery Album (@see https://api.imgur.com/models/gallery_album)
      */
@@ -218,7 +218,7 @@ public function randomGalleryImages($page = 0)
      * @param string $imageOrAlbumId
      * @param array  $data
      *
-     * @link https://api.imgur.com/endpoints/gallery#to-gallery
+     * @see https://api.imgur.com/endpoints/gallery#to-gallery
      *
      * @return bool
      */
@@ -236,7 +236,7 @@ public function submitToGallery($imageOrAlbumId, $data)
      *
      * @param string $imageOrAlbumId
      *
-     * @link https://api.imgur.com/endpoints/gallery#from-gallery
+     * @see https://api.imgur.com/endpoints/gallery#from-gallery
      *
      * @return bool
      */
@@ -250,7 +250,7 @@ public function removeFromGallery($imageOrAlbumId)
      *
      * @param string $albumId
      *
-     * @link https://api.imgur.com/endpoints/gallery#album
+     * @see https://api.imgur.com/endpoints/gallery#album
      *
      * @return array Gallery Album (@see https://api.imgur.com/models/gallery_album)
      */
@@ -264,7 +264,7 @@ public function album($albumId)
      *
      * @param string $imageId
      *
-     * @link https://api.imgur.com/endpoints/gallery#image
+     * @see https://api.imgur.com/endpoints/gallery#image
      *
      * @return array Gallery Image (@see https://api.imgur.com/models/gallery_image)
      */
@@ -278,7 +278,7 @@ public function image($imageId)
      *
      * @param string $imageOrAlbumId
      *
-     * @link https://api.imgur.com/endpoints/gallery#gallery-reporting
+     * @see https://api.imgur.com/endpoints/gallery#gallery-reporting
      *
      * @return bool
      */
@@ -292,7 +292,7 @@ public function report($imageOrAlbumId)
      *
      * @param string $imageOrAlbumId
      *
-     * @link https://api.imgur.com/endpoints/gallery#gallery-votes
+     * @see https://api.imgur.com/endpoints/gallery#gallery-votes
      *
      * @return array Vote (@see https://api.imgur.com/models/vote)
      */
@@ -307,7 +307,7 @@ public function votes($imageOrAlbumId)
      * @param string $imageOrAlbumId
      * @param string $vote           (up | down | veto)
      *
-     * @link https://api.imgur.com/endpoints/gallery#gallery-voting
+     * @see https://api.imgur.com/endpoints/gallery#gallery-voting
      *
      * @return bool
      */
@@ -324,7 +324,7 @@ public function vote($imageOrAlbumId, $vote)
      * @param string $imageOrAlbumId
      * @param string $sort           (best | top | new)
      *
-     * @link https://api.imgur.com/endpoints/gallery#gallery-comments
+     * @see https://api.imgur.com/endpoints/gallery#gallery-comments
      *
      * @return array Array of Comment (@see https://api.imgur.com/endpoints/gallery#gallery-comments)
      */
@@ -341,7 +341,7 @@ public function comments($imageOrAlbumId, $sort = 'best')
      * @param string $imageOrAlbumId
      * @param string $commentId
      *
-     * @link https://api.imgur.com/endpoints/gallery#gallery-comment
+     * @see https://api.imgur.com/endpoints/gallery#gallery-comment
      *
      * @return array Comment (@see https://api.imgur.com/endpoints/gallery#gallery-comments)
      */
@@ -356,7 +356,7 @@ public function comment($imageOrAlbumId, $commentId)
      * @param string $imageOrAlbumId
      * @param array  $data
      *
-     * @link https://api.imgur.com/endpoints/gallery#gallery-comment-creation
+     * @see https://api.imgur.com/endpoints/gallery#gallery-comment-creation
      *
      * @return bool
      */
@@ -376,7 +376,7 @@ public function createComment($imageOrAlbumId, $data)
      * @param string $commentId
      * @param array  $data
      *
-     * @link https://api.imgur.com/endpoints/gallery#gallery-comment-reply
+     * @see https://api.imgur.com/endpoints/gallery#gallery-comment-reply
      *
      * @return bool
      */
@@ -394,7 +394,7 @@ public function createReply($imageOrAlbumId, $commentId, $data)
      *
      * @param string $imageOrAlbumId
      *
-     * @link https://api.imgur.com/endpoints/gallery#gallery-comment-ids
+     * @see https://api.imgur.com/endpoints/gallery#gallery-comment-ids
      *
      * @return array<int>
      */
@@ -408,7 +408,7 @@ public function commentIds($imageOrAlbumId)
      *
      * @param string $imageOrAlbumId
      *
-     * @link https://api.imgur.com/endpoints/gallery#gallery-comment-count
+     * @see https://api.imgur.com/endpoints/gallery#gallery-comment-count
      *
      * @return int
      */
diff --git a/lib/Imgur/Api/Image.php b/lib/Imgur/Api/Image.php
index ee09548..fdbbe35 100644
--- a/lib/Imgur/Api/Image.php
+++ b/lib/Imgur/Api/Image.php
@@ -8,7 +8,7 @@
 /**
  * CRUD for Images.
  *
- * @link https://api.imgur.com/endpoints/image
+ * @see https://api.imgur.com/endpoints/image
  *
  * @author Adrian Ghiuta <adrian.ghiuta@gmail.com>
  */
@@ -19,7 +19,7 @@ class Image extends AbstractApi
      *
      * @param string $imageId
      *
-     * @link https://api.imgur.com/endpoints/image#image
+     * @see https://api.imgur.com/endpoints/image#image
      *
      * @return array (@see https://api.imgur.com/models/image)
      */
@@ -33,7 +33,7 @@ public function image($imageId)
      *
      * @param array $data
      *
-     * @link https://api.imgur.com/endpoints/image#image-upload
+     * @see https://api.imgur.com/endpoints/image#image-upload
      *
      * @return bool
      */
@@ -44,7 +44,7 @@ public function upload($data)
         }
 
         $typeValues = ['file', 'base64', 'url'];
-        if (isset($data['type']) && !in_array(strtolower($data['type']), $typeValues, true)) {
+        if (isset($data['type']) && !\in_array(strtolower($data['type']), $typeValues, true)) {
             throw new InvalidArgumentException('Type parameter "' . $data['type'] . '" is wrong. Possible values are: ' . implode(', ', $typeValues));
         }
 
@@ -61,7 +61,7 @@ public function upload($data)
      *
      * @param string $imageIdOrDeleteHash
      *
-     * @link https://api.imgur.com/endpoints/image#image-delete
+     * @see https://api.imgur.com/endpoints/image#image-delete
      *
      * @return bool
      */
@@ -78,7 +78,7 @@ public function deleteImage($imageIdOrDeleteHash)
      * @param string $imageIdOrDeleteHash
      * @param array  $data
      *
-     * @link https://api.imgur.com/endpoints/image#image-update
+     * @see https://api.imgur.com/endpoints/image#image-update
      *
      * @return bool
      */
@@ -92,7 +92,7 @@ public function update($imageIdOrDeleteHash, $data)
      *
      * @param string $imageIdOrDeleteHash
      *
-     * @link https://api.imgur.com/endpoints/image#image-favorite
+     * @see https://api.imgur.com/endpoints/image#image-favorite
      *
      * @return bool
      */
diff --git a/lib/Imgur/Api/Memegen.php b/lib/Imgur/Api/Memegen.php
index dd7a09a..4606c2b 100644
--- a/lib/Imgur/Api/Memegen.php
+++ b/lib/Imgur/Api/Memegen.php
@@ -5,7 +5,7 @@
 /**
  * CRUD for Memegen.
  *
- * @link https://api.imgur.com/endpoints/memegen
+ * @see https://api.imgur.com/endpoints/memegen
  *
  * @author Adrian Ghiuta <adrian.ghiuta@gmail.com>
  */
@@ -14,7 +14,7 @@ class Memegen extends AbstractApi
     /**
      * Get the list of default memes.
      *
-     * @link https://api.imgur.com/endpoints/memegen#defaults
+     * @see https://api.imgur.com/endpoints/memegen#defaults
      *
      * @return array Of images (@see Image.php)
      */
diff --git a/lib/Imgur/Api/Notification.php b/lib/Imgur/Api/Notification.php
index d3eac01..c412954 100644
--- a/lib/Imgur/Api/Notification.php
+++ b/lib/Imgur/Api/Notification.php
@@ -5,7 +5,7 @@
 /**
  * CRUD for Notifications.
  *
- * @link https://api.imgur.com/endpoints/notification
+ * @see https://api.imgur.com/endpoints/notification
  *
  * @author Adrian Ghiuta <adrian.ghiuta@gmail.com>
  */
@@ -16,7 +16,7 @@ class Notification extends AbstractApi
      *
      * @param string $new false for all notifications, true for only non-viewed notification
      *
-     * @link https://api.imgur.com/endpoints/notification#notifications
+     * @see https://api.imgur.com/endpoints/notification#notifications
      *
      * @return array With keys "replies" & "messages"
      */
@@ -32,7 +32,7 @@ public function notifications($new = true)
      *
      * @param string $notificationId
      *
-     * @link https://api.imgur.com/endpoints/notification#notification
+     * @see https://api.imgur.com/endpoints/notification#notification
      *
      * @return array (@see https://api.imgur.com/models/notification)
      */
@@ -46,7 +46,7 @@ public function notification($notificationId)
      *
      * @param string $notificationId
      *
-     * @link https://api.imgur.com/endpoints/notification#notification-viewed
+     * @see https://api.imgur.com/endpoints/notification#notification-viewed
      *
      * @return bool
      */
diff --git a/lib/Imgur/Api/Topic.php b/lib/Imgur/Api/Topic.php
index d81a86f..df484bc 100644
--- a/lib/Imgur/Api/Topic.php
+++ b/lib/Imgur/Api/Topic.php
@@ -5,14 +5,14 @@
 /**
  * CRUD for Topic.
  *
- * @link https://api.imgur.com/endpoints/topic
+ * @see https://api.imgur.com/endpoints/topic
  */
 class Topic extends AbstractApi
 {
     /**
      * Get the list of default topics.
      *
-     * @link https://api.imgur.com/endpoints/topic#defaults
+     * @see https://api.imgur.com/endpoints/topic#defaults
      *
      * @return array Topic (@see https://api.imgur.com/models/topic)
      */
@@ -29,7 +29,7 @@ public function defaultTopics()
      * @param int    $page
      * @param string $window  (day | week | month | year | all)
      *
-     * @link https://api.imgur.com/endpoints/topic#gallery-topic
+     * @see https://api.imgur.com/endpoints/topic#gallery-topic
      *
      * @return array Gallery Image (@see https://api.imgur.com/models/gallery_image) OR Gallery Album (@see https://api.imgur.com/models/gallery_album)
      */
@@ -47,7 +47,7 @@ public function galleryTopic($topicId, $sort = 'viral', $page = 0, $window = 'we
      * @param string $topicId The ID or URL-formatted name of the topic. If using a topic's name, replace its spaces with underscores (Mother's_Day)
      * @param int    $itemId  The ID for the gallery item
      *
-     * @link https://api.imgur.com/endpoints/topic#gallery-topic-item
+     * @see https://api.imgur.com/endpoints/topic#gallery-topic-item
      *
      * @return array Gallery Image (@see https://api.imgur.com/models/gallery_image) OR Gallery Album (@see https://api.imgur.com/models/gallery_album)
      */
diff --git a/lib/Imgur/Auth/AuthInterface.php b/lib/Imgur/Auth/AuthInterface.php
index d5f178c..d11d71a 100644
--- a/lib/Imgur/Auth/AuthInterface.php
+++ b/lib/Imgur/Auth/AuthInterface.php
@@ -20,11 +20,14 @@ interface AuthInterface
     public function getAuthenticationUrl($responseType = 'code', $state = null);
 
     public function getAccessToken();
+
     public function requestAccessToken($code, $responseType);
+
     public function setAccessToken($accessToken);
 
     public function sign();
 
     public function refreshToken();
+
     public function checkAccessTokenExpired();
 }
diff --git a/lib/Imgur/Auth/OAuth2.php b/lib/Imgur/Auth/OAuth2.php
index 26829c1..d0787cd 100644
--- a/lib/Imgur/Auth/OAuth2.php
+++ b/lib/Imgur/Auth/OAuth2.php
@@ -13,6 +13,9 @@
  */
 class OAuth2 implements AuthInterface
 {
+    const AUTHORIZATION_ENDPOINT = 'https://api.imgur.com/oauth2/authorize';
+    const ACCESS_TOKEN_ENDPOINT = 'https://api.imgur.com/oauth2/token';
+
     /**
      * Indicates the client that is making the request.
      *
@@ -57,9 +60,6 @@ class OAuth2 implements AuthInterface
      */
     private $token;
 
-    const AUTHORIZATION_ENDPOINT = 'https://api.imgur.com/oauth2/authorize';
-    const ACCESS_TOKEN_ENDPOINT = 'https://api.imgur.com/oauth2/token';
-
     /**
      * Instantiates the OAuth2 class, but does not trigger the authentication process.
      *
@@ -78,7 +78,7 @@ public function __construct(HttpClientInterface $httpClient, $clientId, $clientS
      * Generates the authentication URL to which a user should be pointed at in order to start the OAuth2 process.
      *
      * @param string      $responseType
-     * @param null|string $state
+     * @param string|null $state
      *
      * @return string
      */
@@ -110,7 +110,6 @@ public function requestAccessToken($code, $requestType)
                 $grantType = 'pin';
                 $type = 'pin';
                 break;
-
             case 'code':
             default:
                 $grantType = 'authorization_code';
@@ -190,7 +189,7 @@ public function refreshToken()
      */
     public function setAccessToken($token)
     {
-        if (!is_array($token)) {
+        if (!\is_array($token)) {
             throw new AuthException('Token is not a valid json string.');
         }
 
diff --git a/lib/Imgur/Client.php b/lib/Imgur/Client.php
index 0e10597..b762f7f 100644
--- a/lib/Imgur/Client.php
+++ b/lib/Imgur/Client.php
@@ -39,7 +39,7 @@ class Client
     /**
      * Instantiate a new Imgur client.
      *
-     * @param null|HttpClientInterface $httpClient Imgur http client
+     * @param HttpClientInterface|null $httpClient Imgur http client
      */
     public function __construct(AuthInterface $authenticationClient = null, HttpClientInterface $httpClient = null)
     {
@@ -98,7 +98,7 @@ public function setHttpClient(HttpClientInterface $httpClient)
      */
     public function getOption($name)
     {
-        if (!array_key_exists($name, $this->options)) {
+        if (!\array_key_exists($name, $this->options)) {
             throw new InvalidArgumentException(sprintf('Undefined option called: "%s"', $name));
         }
 
@@ -113,7 +113,7 @@ public function getOption($name)
      */
     public function setOption($name, $value)
     {
-        if (!array_key_exists($name, $this->options)) {
+        if (!\array_key_exists($name, $this->options)) {
             throw new InvalidArgumentException(sprintf('Undefined option called: "%s"', $name));
         }
 
diff --git a/lib/Imgur/Exception/MissingArgumentException.php b/lib/Imgur/Exception/MissingArgumentException.php
index 707c1b8..50a00f3 100644
--- a/lib/Imgur/Exception/MissingArgumentException.php
+++ b/lib/Imgur/Exception/MissingArgumentException.php
@@ -6,7 +6,7 @@ class MissingArgumentException extends ErrorException
 {
     public function __construct($required, $code = 0, $previous = null)
     {
-        if (is_string($required)) {
+        if (\is_string($required)) {
             $required = [$required];
         }
 
diff --git a/lib/Imgur/HttpClient/HttpClient.php b/lib/Imgur/HttpClient/HttpClient.php
index bb122a3..f84e098 100644
--- a/lib/Imgur/HttpClient/HttpClient.php
+++ b/lib/Imgur/HttpClient/HttpClient.php
@@ -116,7 +116,7 @@ public function createRequest($url, $parameters, $httpMethod = 'GET')
             $options['query'] = $parameters['query'];
         }
 
-        if ($httpMethod === 'POST' || $httpMethod === 'PUT' || $httpMethod === 'DELETE') {
+        if ('POST' === $httpMethod || 'PUT' === $httpMethod || 'DELETE' === $httpMethod) {
             $options['body'] = $parameters;
         }
 
diff --git a/lib/Imgur/Listener/AuthListener.php b/lib/Imgur/Listener/AuthListener.php
index f6bc3e6..f87ee0f 100644
--- a/lib/Imgur/Listener/AuthListener.php
+++ b/lib/Imgur/Listener/AuthListener.php
@@ -19,7 +19,7 @@ public function before(BeforeEvent $event)
     {
         $request = $event->getRequest();
 
-        if (is_array($this->token) && !empty($this->token['access_token'])) {
+        if (\is_array($this->token) && !empty($this->token['access_token'])) {
             $request->setHeader(
                 'Authorization',
                 'Bearer ' . $this->token['access_token']
diff --git a/lib/Imgur/Listener/ErrorListener.php b/lib/Imgur/Listener/ErrorListener.php
index 58abb92..6c34acb 100644
--- a/lib/Imgur/Listener/ErrorListener.php
+++ b/lib/Imgur/Listener/ErrorListener.php
@@ -32,14 +32,16 @@ public function error(ErrorEvent $event)
             $responseData = $body;
         }
 
-        if (is_array($responseData) && isset($responseData['data']) && isset($responseData['data']['error'])) {
-            throw new ErrorException(
-                'Request to: ' . $responseData['data']['request'] . ' failed with: "' . $responseData['data']['error'] . '"',
-                $response->getStatusCode()
-            );
+        if (\is_array($responseData) && isset($responseData['data']) && isset($responseData['data']['error'])) {
+            $message = 'Request failed with: "' . $responseData['data']['error'] . '"';
+            if (isset($responseData['data']['request'])) {
+                $message = 'Request to: ' . $responseData['data']['request'] . ' failed with: "' . $responseData['data']['error'] . '"';
+            }
+
+            throw new ErrorException($message, $response->getStatusCode());
         }
 
-        throw new RuntimeException(is_array($responseData) && isset($responseData['message']) ? $responseData['message'] : $responseData, $response->getStatusCode());
+        throw new RuntimeException(\is_array($responseData) && isset($responseData['message']) ? $responseData['message'] : $responseData, $response->getStatusCode());
     }
 
     /**
diff --git a/tests/Api/AbstractApiTest.php b/tests/Api/AbstractApiTest.php
index e3200b1..131cac9 100644
--- a/tests/Api/AbstractApiTest.php
+++ b/tests/Api/AbstractApiTest.php
@@ -6,7 +6,7 @@
 use Imgur\Client;
 use Imgur\Pager\BasicPager;
 
-class AbstractApiTest extends \PHPUnit_Framework_TestCase
+class AbstractApiTest extends \PHPUnit\Framework\TestCase
 {
     public function testGet()
     {
diff --git a/tests/Api/AccountTest.php b/tests/Api/AccountTest.php
index 3174270..e554c51 100644
--- a/tests/Api/AccountTest.php
+++ b/tests/Api/AccountTest.php
@@ -12,11 +12,6 @@
 
 class AccountTest extends ApiTestCase
 {
-    protected function getApiClass()
-    {
-        return 'Imgur\Api\Account';
-    }
-
     /**
      * @expectedException \Imgur\Exception\ErrorException
      * @expectedExceptionMessage Authentication required
@@ -633,4 +628,9 @@ public function testReplies()
 
         $this->assertSame($expectedValue, $api->replies());
     }
+
+    protected function getApiClass()
+    {
+        return 'Imgur\Api\Account';
+    }
 }
diff --git a/tests/Api/AlbumOrImageTest.php b/tests/Api/AlbumOrImageTest.php
index b1d5b69..c5b4517 100644
--- a/tests/Api/AlbumOrImageTest.php
+++ b/tests/Api/AlbumOrImageTest.php
@@ -10,7 +10,7 @@
 use Imgur\Client;
 use Imgur\HttpClient\HttpClient;
 
-class AlbumOrImageTest extends \PHPUnit_Framework_TestCase
+class AlbumOrImageTest extends \PHPUnit\Framework\TestCase
 {
     public function testWithImageId()
     {
diff --git a/tests/Api/AlbumTest.php b/tests/Api/AlbumTest.php
index cbe26d0..7b5e639 100644
--- a/tests/Api/AlbumTest.php
+++ b/tests/Api/AlbumTest.php
@@ -12,11 +12,6 @@
 
 class AlbumTest extends ApiTestCase
 {
-    protected function getApiClass()
-    {
-        return 'Imgur\Api\Album';
-    }
-
     /**
      * @expectedException \Imgur\Exception\ErrorException
      * @expectedExceptionMessage Authentication required
@@ -298,4 +293,9 @@ public function testRemoveImages()
 
         $this->assertSame($expectedValue, $api->removeImages('VOMXz', ['POvvB', 'P1vvB']));
     }
+
+    protected function getApiClass()
+    {
+        return 'Imgur\Api\Album';
+    }
 }
diff --git a/tests/Api/ApiTestCase.php b/tests/Api/ApiTestCase.php
index 9af6c0f..8f68f96 100644
--- a/tests/Api/ApiTestCase.php
+++ b/tests/Api/ApiTestCase.php
@@ -4,7 +4,7 @@
 
 use Imgur\Client;
 
-abstract class ApiTestCase extends \PHPUnit_Framework_TestCase
+abstract class ApiTestCase extends \PHPUnit\Framework\TestCase
 {
     abstract protected function getApiClass();
 
diff --git a/tests/Api/CommentTest.php b/tests/Api/CommentTest.php
index 6efa396..3a3c6dd 100644
--- a/tests/Api/CommentTest.php
+++ b/tests/Api/CommentTest.php
@@ -12,11 +12,6 @@
 
 class CommentTest extends ApiTestCase
 {
-    protected function getApiClass()
-    {
-        return 'Imgur\Api\Comment';
-    }
-
     /**
      * @expectedException \Imgur\Exception\ErrorException
      * @expectedExceptionMessage Authentication required
@@ -233,4 +228,9 @@ public function testReport()
 
         $this->assertSame($expectedValue, $api->report('726305564'));
     }
+
+    protected function getApiClass()
+    {
+        return 'Imgur\Api\Comment';
+    }
 }
diff --git a/tests/Api/ConversationTest.php b/tests/Api/ConversationTest.php
index cfa5ad2..560c642 100644
--- a/tests/Api/ConversationTest.php
+++ b/tests/Api/ConversationTest.php
@@ -12,11 +12,6 @@
 
 class ConversationTest extends ApiTestCase
 {
-    protected function getApiClass()
-    {
-        return 'Imgur\Api\Conversation';
-    }
-
     /**
      * @expectedException \Imgur\Exception\ErrorException
      * @expectedExceptionMessage Authentication required
@@ -182,4 +177,9 @@ public function testBlockSender()
 
         $this->assertSame($expectedValue, $api->blockSender('imgur'));
     }
+
+    protected function getApiClass()
+    {
+        return 'Imgur\Api\Conversation';
+    }
 }
diff --git a/tests/Api/CustomGalleryTest.php b/tests/Api/CustomGalleryTest.php
index c6ac3d1..520d317 100644
--- a/tests/Api/CustomGalleryTest.php
+++ b/tests/Api/CustomGalleryTest.php
@@ -12,11 +12,6 @@
 
 class CustomGalleryTest extends ApiTestCase
 {
-    protected function getApiClass()
-    {
-        return 'Imgur\Api\CustomGallery';
-    }
-
     /**
      * @expectedException \Imgur\Exception\ErrorException
      * @expectedExceptionMessage Authentication required
@@ -255,4 +250,9 @@ public function testUnBlockTag()
 
         $this->assertSame($expectedValue, $api->unBlockTag('funny'));
     }
+
+    protected function getApiClass()
+    {
+        return 'Imgur\Api\CustomGallery';
+    }
 }
diff --git a/tests/Api/GalleryTest.php b/tests/Api/GalleryTest.php
index b3959fb..c70004f 100644
--- a/tests/Api/GalleryTest.php
+++ b/tests/Api/GalleryTest.php
@@ -12,11 +12,6 @@
 
 class GalleryTest extends ApiTestCase
 {
-    protected function getApiClass()
-    {
-        return 'Imgur\Api\Gallery';
-    }
-
     /**
      * @expectedException \Imgur\Exception\ErrorException
      * @expectedExceptionMessage Authentication required
@@ -709,4 +704,9 @@ public function testCommentCount()
 
         $this->assertSame($expectedValue, $api->commentCount('VOMXz'));
     }
+
+    protected function getApiClass()
+    {
+        return 'Imgur\Api\Gallery';
+    }
 }
diff --git a/tests/Api/ImageTest.php b/tests/Api/ImageTest.php
index d71bdda..8032184 100644
--- a/tests/Api/ImageTest.php
+++ b/tests/Api/ImageTest.php
@@ -12,11 +12,6 @@
 
 class ImageTest extends ApiTestCase
 {
-    protected function getApiClass()
-    {
-        return 'Imgur\Api\Image';
-    }
-
     /**
      * @expectedException \Imgur\Exception\ErrorException
      * @expectedExceptionMessage Authentication required
@@ -217,4 +212,9 @@ public function testFavorite()
 
         $this->assertSame($expectedValue, $api->favorite('ZOY11VC'));
     }
+
+    protected function getApiClass()
+    {
+        return 'Imgur\Api\Image';
+    }
 }
diff --git a/tests/Api/MemegenTest.php b/tests/Api/MemegenTest.php
index ab55903..ef7e6ae 100644
--- a/tests/Api/MemegenTest.php
+++ b/tests/Api/MemegenTest.php
@@ -12,11 +12,6 @@
 
 class MemegenTest extends ApiTestCase
 {
-    protected function getApiClass()
-    {
-        return 'Imgur\Api\Memegen';
-    }
-
     /**
      * @expectedException \Imgur\Exception\ErrorException
      * @expectedExceptionMessage Authentication required
@@ -112,4 +107,9 @@ public function testMemegen()
 
         $this->assertSame($expectedValue, $api->defaultMemes());
     }
+
+    protected function getApiClass()
+    {
+        return 'Imgur\Api\Memegen';
+    }
 }
diff --git a/tests/Api/NotificationTest.php b/tests/Api/NotificationTest.php
index 2803441..2ba5345 100644
--- a/tests/Api/NotificationTest.php
+++ b/tests/Api/NotificationTest.php
@@ -12,11 +12,6 @@
 
 class NotificationTest extends ApiTestCase
 {
-    protected function getApiClass()
-    {
-        return 'Imgur\Api\Notification';
-    }
-
     /**
      * @expectedException \Imgur\Exception\ErrorException
      * @expectedExceptionMessage Authentication required
@@ -143,4 +138,9 @@ public function testNotificationViewed()
 
         $this->assertSame($expectedValue, $api->notificationViewed('76878181'));
     }
+
+    protected function getApiClass()
+    {
+        return 'Imgur\Api\Notification';
+    }
 }
diff --git a/tests/Api/TopicTest.php b/tests/Api/TopicTest.php
index d28406b..18feb22 100644
--- a/tests/Api/TopicTest.php
+++ b/tests/Api/TopicTest.php
@@ -12,11 +12,6 @@
 
 class TopicTest extends ApiTestCase
 {
-    protected function getApiClass()
-    {
-        return 'Imgur\Api\Topic';
-    }
-
     /**
      * @expectedException \Imgur\Exception\ErrorException
      * @expectedExceptionMessage Authentication required
@@ -204,4 +199,9 @@ public function testGalleryTopicItem()
 
         $this->assertSame($expectedValue, $api->galleryTopicItem(155, 'Fbae9SG'));
     }
+
+    protected function getApiClass()
+    {
+        return 'Imgur\Api\Topic';
+    }
 }
diff --git a/tests/Auth/OAuth2Test.php b/tests/Auth/OAuth2Test.php
index 7a07e80..8fd17b4 100644
--- a/tests/Auth/OAuth2Test.php
+++ b/tests/Auth/OAuth2Test.php
@@ -9,7 +9,7 @@
 use Imgur\Auth\OAuth2;
 use Imgur\HttpClient\HttpClient;
 
-class OAuth2Test extends \PHPUnit_Framework_TestCase
+class OAuth2Test extends \PHPUnit\Framework\TestCase
 {
     public function testGetAuthenticationUrl()
     {
@@ -165,5 +165,7 @@ public function testAuthenticatedRequest()
         $auth->requestAccessToken('code', null);
 
         $httpClient->get('http://google.com');
+
+        $this->assertTrue($auth->checkAccessTokenExpired());
     }
 }
diff --git a/tests/ClientTest.php b/tests/ClientTest.php
index bc9ae60..0aea8d3 100644
--- a/tests/ClientTest.php
+++ b/tests/ClientTest.php
@@ -4,34 +4,8 @@
 
 use Imgur\Client;
 
-class ClientTest extends \PHPUnit_Framework_TestCase
+class ClientTest extends \PHPUnit\Framework\TestCase
 {
-    private function getHttpClientMock(array $methods = [])
-    {
-        $methods = array_merge(
-            ['get', 'post', 'delete', 'request', 'performRequest', 'createRequest', 'parseResponse'],
-            $methods
-        );
-
-        return $this->getMockBuilder('Imgur\HttpClient\HttpClient')
-            ->disableOriginalConstructor()
-            ->setMethods($methods)
-            ->getMock();
-    }
-
-    private function getAuthenticationClientMock(array $methods = [])
-    {
-        $methods = array_merge(
-            ['getAuthenticationUrl', 'getAccessToken', 'requestAccessToken', 'setAccessToken', 'sign', 'refreshToken'],
-            $methods
-        );
-
-        return $this->getMockBuilder('Imgur\Auth\OAuth2')
-            ->disableOriginalConstructor()
-            ->setMethods($methods)
-            ->getMock();
-    }
-
     public function testNoParameters()
     {
         $client = new Client();
@@ -191,4 +165,30 @@ public function testSetAccessToken()
         $client = new Client($authenticationClient, $httpClient);
         $client->setAccessToken('token');
     }
+
+    private function getHttpClientMock(array $methods = [])
+    {
+        $methods = array_merge(
+            ['get', 'post', 'delete', 'request', 'performRequest', 'createRequest', 'parseResponse'],
+            $methods
+        );
+
+        return $this->getMockBuilder('Imgur\HttpClient\HttpClient')
+            ->disableOriginalConstructor()
+            ->setMethods($methods)
+            ->getMock();
+    }
+
+    private function getAuthenticationClientMock(array $methods = [])
+    {
+        $methods = array_merge(
+            ['getAuthenticationUrl', 'getAccessToken', 'requestAccessToken', 'setAccessToken', 'sign', 'refreshToken'],
+            $methods
+        );
+
+        return $this->getMockBuilder('Imgur\Auth\OAuth2')
+            ->disableOriginalConstructor()
+            ->setMethods($methods)
+            ->getMock();
+    }
 }
diff --git a/tests/HttpClient/HttpClientTest.php b/tests/HttpClient/HttpClientTest.php
index 7b02e95..e8e91a8 100644
--- a/tests/HttpClient/HttpClientTest.php
+++ b/tests/HttpClient/HttpClientTest.php
@@ -8,7 +8,7 @@
 use GuzzleHttp\Subscriber\Mock;
 use Imgur\HttpClient\HttpClient;
 
-class HttpClientTest extends \PHPUnit_Framework_TestCase
+class HttpClientTest extends \PHPUnit\Framework\TestCase
 {
     public function testOptionsToConstructor()
     {
diff --git a/tests/Listener/AuthListenerTest.php b/tests/Listener/AuthListenerTest.php
index 2a9ad3f..4b43e2b 100644
--- a/tests/Listener/AuthListenerTest.php
+++ b/tests/Listener/AuthListenerTest.php
@@ -3,10 +3,9 @@
 namespace Imgur\Tests\HttpClient;
 
 use GuzzleHttp\Message\Request;
-use Imgur\Client;
 use Imgur\Listener\AuthListener;
 
-class AuthListenerTest extends \PHPUnit_Framework_TestCase
+class AuthListenerTest extends \PHPUnit\Framework\TestCase
 {
     public function testDefineClientIdOnBadToken()
     {
diff --git a/tests/Listener/ErrorListenerTest.php b/tests/Listener/ErrorListenerTest.php
index c2a333e..123a3cd 100644
--- a/tests/Listener/ErrorListenerTest.php
+++ b/tests/Listener/ErrorListenerTest.php
@@ -5,7 +5,7 @@
 use Guzzle\Http\Message\Request;
 use Imgur\Listener\ErrorListener;
 
-class ErrorListenerTest extends \PHPUnit_Framework_TestCase
+class ErrorListenerTest extends \PHPUnit\Framework\TestCase
 {
     public function testNothinHappenOnOKResponse()
     {
@@ -118,6 +118,42 @@ public function testErrorWithJson()
         $listener->error($this->getEventMock($response));
     }
 
+    /**
+     * @expectedException \Imgur\Exception\ErrorException
+     * @expectedExceptionMessage Request failed with: "Imgur is temporarily over capacity. Please try again later."
+     */
+    public function testErrorOverCapacity()
+    {
+        $response = $this->getMockBuilder('GuzzleHttp\Message\ResponseInterface')
+            ->disableOriginalConstructor()
+            ->getMock();
+        $response->expects($this->exactly(2))
+            ->method('getStatusCode')
+            ->will($this->returnValue(429));
+        $response->expects($this->once())
+            ->method('getBody')
+            ->will($this->returnValue(json_encode(['status' => 500, 'success' => false, 'data' => ['error' => 'Imgur is temporarily over capacity. Please try again later.']])));
+        $response->expects($this->at(1))
+            ->method('getHeader')
+            ->with('X-RateLimit-UserRemaining')
+            ->will($this->returnValue(9));
+        $response->expects($this->at(2))
+            ->method('getHeader')
+            ->with('X-RateLimit-UserLimit')
+            ->will($this->returnValue(10));
+        $response->expects($this->at(3))
+            ->method('getHeader')
+            ->with('X-RateLimit-ClientRemaining')
+            ->will($this->returnValue(9));
+        $response->expects($this->at(4))
+            ->method('getHeader')
+            ->with('X-RateLimit-ClientLimit')
+            ->will($this->returnValue(10));
+
+        $listener = new ErrorListener();
+        $listener->error($this->getEventMock($response));
+    }
+
     /**
      * @expectedException \Imgur\Exception\RuntimeException
      * @expectedExceptionMessage hihi