fixed error

Author: wrisa

instrumentation-genai/opentelemetry-instrumentation-langchain/src/opentelemetry/instrumentation/langchain/callback_handler.py

@@ -77,8 +77,9 @@ def on_chain_start(
             self._invocation_manager.add_invocation_state(run_id, None, wf)
             return
         else:
+            # TODO: For agent invocation
             self._invocation_manager.add_invocation_state(
-                run_id, parent_run_id
+                run_id, parent_run_id,
             )
 
     def on_chain_end(

instrumentation-genai/opentelemetry-instrumentation-langchain/src/opentelemetry/instrumentation/langchain/invocation_manager.py

@@ -39,7 +39,7 @@ def add_invocation_state(
         self,
         run_id: UUID,
         parent_run_id: Optional[UUID],
-        invocation: GenAIInvocation,
+        invocation: GenAIInvocation = None,
     ):
         invocation_state = _InvocationState(invocation=invocation)
         self._invocations[run_id] = invocation_state