feat(persistence): refine Graph definition

Author: bsorrentino

how-tos/persistence.ipynb

@@ -162,31 +162,6 @@
     "        // This is a placeholder for the actual implementation\n",
     "        return \"Cold, with a low of 13 degrees\";\n",
     "    }\n",
-    "}\n",
-    "\n",
-    "public recoord ToolInfo( ToolSpecification specification; ToolExecutor executor )\n",
-    "\n",
-    "    public static List<ToolInfo> of( Object ...objectsWithTools) {\n",
-    "        return fromArray( (Object[])objectsWithTools );\n",
-    "    }\n",
-    "    public static List<ToolInfo> fromArray( Object[] objectsWithTools ) {\n",
-    "        List<ToolInfo> toolSpecifications = new ArrayList<>();\n",
-    "\n",
-    "        for (Object objectWithTools : objectsWithTools) {\n",
-    "            for (Method method : objectWithTools.getClass().getDeclaredMethods()) {\n",
-    "                if (method.isAnnotationPresent(Tool.class)) {\n",
-    "                    ToolSpecification toolSpecification = toolSpecificationFrom(method);\n",
-    "                    ToolExecutor executor = new DefaultToolExecutor(objectWithTools, method);\n",
-    "                    toolSpecifications.add( new ToolInfo( toolSpecification, executor));\n",
-    "                }\n",
-    "            }\n",
-    "        }\n",
-    "        return unmodifiableList(toolSpecifications);\n",
-    "    }\n",
-    "    public static List<ToolInfo> fromList(List<Object> objectsWithTools ) {\n",
-    "        return fromArray(objectsWithTools.toArray());\n",
-    "    }\n",
-    "\n",
     "}"
    ]
   },
@@ -279,10 +254,13 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 88,
+   "execution_count": null,
    "metadata": {},
    "outputs": [],
    "source": [
+    "import static org.bsc.langgraph4j.StateGraph.START;\n",
+    "import static org.bsc.langgraph4j.StateGraph.END;\n",
+    "import org.bsc.langgraph4j.StateGraph;\n",
     "import org.bsc.langgraph4j.action.EdgeAction;\n",
     "import static org.bsc.langgraph4j.action.AsyncEdgeAction.edge_async;\n",
     "import org.bsc.langgraph4j.action.NodeAction;\n",
@@ -294,15 +272,19 @@
     "// Route Message \n",
     "EdgeAction<MessageState> routeMessage = state -> {\n",
     "  \n",
-    "  Optional<AiMessage> lastMessage = state.lastMessage();\n",
+    "  var lastMessage = state.lastMessage();\n",
     "  \n",
-    "  if ( lastMessage.isPresent()) {\n",
+    "  if ( !lastMessage.isPresent()) {\n",
     "    return \"exit\";\n",
     "  }\n",
+    "\n",
+    "  var message = (AiMessage)lastMessage.get();\n",
+    "\n",
     "  // If no tools are called, we can finish (respond to the user)\n",
-    "  if ( !lastMessage.get().hasToolExecutionRequests() ) {\n",
+    "  if ( !message.hasToolExecutionRequests() ) {\n",
     "    return \"exit\";\n",
     "  }\n",
+    "  \n",
     "  // Otherwise if there is, we continue and call the tools\n",
     "  return \"next\";\n",
     "};\n",
@@ -323,7 +305,8 @@
     "// Invoke Tool \n",
     "NodeAction<MessageState> invokeTool = state -> {\n",
     "\n",
-    "  var lastMessage = (AiMessage)state.lastMessage().orElseThrow( () -> ( new IllegalStateException( \"last message not found!\")) );\n",
+    "  var lastMessage = (AiMessage)state.lastMessage()\n",
+    "                          .orElseThrow( () -> ( new IllegalStateException( \"last message not found!\")) );\n",
     "\n",
     "  var executionRequest = lastMessage.toolExecutionRequests().get(0);\n",
     "\n",