Update node handling for better error management.

mindsearch/agent/graph.py

@@ -303,5 +303,19 @@ class ExecutionAction(BaseAction):
                             ),
                             stream_state=AgentStatusCode.STREAM_ING,
                         )
-        res = [graph.nodes[node.strip().strip('"').strip("'")] for node in node_list]
+        #res = [graph.nodes[node.strip().strip('"').strip("'")] for node in node_list]
+        res = []
+        missing_nodes = []
+        for node in node_list:
+            node_key = node.strip().strip('"').strip("'")
+            if node_key in graph.nodes:
+                res.append(graph.nodes[node_key])
+            else:
+                missing_nodes.append(node_key)
+        
+        if missing_nodes:
+            print(f"Warning: The following nodes are missing: {missing_nodes}")
+            # Optionally, raise an exception or handle missing nodes as needed
+            raise KeyError(f"Missing nodes in graph: {missing_nodes}")
+
         return res, graph.nodes, graph.adjacency_list