add human message in template

lang_agent/base.py

@@ -139,18 +139,28 @@ class GraphBase(ABC):
     
     def _agent_call_template(self, system_prompt:str,
                                   model:CompiledStateGraph, 
-                                  state:State):
+                                  state:State,
+                                  human_msg:str = None):
         if state.get("messages") is not None:
             inp = state["messages"], state["inp"][1]
         else:
             inp = state["inp"]
         
-        inp = {"messages":[
-                    SystemMessage(
-                        system_prompt
-                    ),
-                    *state["inp"][0]["messages"][1:]
-                ]}, state["inp"][1]
+        if human_msg is None:
+            inp = {"messages":[
+                        SystemMessage(
+                            system_prompt
+                        ),
+                        *state["inp"][0]["messages"][1:]
+                    ]}, state["inp"][1]
+        else:
+            inp = {"messages":[
+                        SystemMessage(
+                            system_prompt
+                        ),
+                        *state["inp"][0]["messages"][1:],
+                        HumanMessage(human_msg)
+                    ]}, state["inp"][1]
 
 
         out = model.invoke(*inp)