fix(stream_chunk_builder): adding support for tool calling in completion counting

litellm/utils.py

@@ -140,12 +140,16 @@ class Message(OpenAIObject):
         self.role = role
         if function_call is not None: 
             self.function_call = FunctionCall(**function_call)
+        else: 
+            self.function_call = None
         if tool_calls is not None:
             self.tool_calls = []
             for tool_call in tool_calls:
                 self.tool_calls.append(
                     ChatCompletionMessageToolCall(**tool_call)
                 )
+        else:
+            self.tool_calls = None
         if logprobs is not None:
             self._logprobs = logprobs