trace doesn't work with .batch handler on langserve

[restuprajna]

I'm using langserve and make two handler using .invoke and .batch, the trace is working fine for invoke but seem doesn't show record with the .batch handler

from langserve import APIHandler
langfuse_config = RunnableConfig(callbacks=[langfuse_handler]

async def batch_api(api_chain, path: str, request: Request) -> Response:
    api_handler = APIHandler(api_chain, path=path, include_callback_events=True)
    return await api_handler.batch(request, server_config=langfuse_config)
    
async def invoke_api(api_chain, path: str, request: Request) -> Response:
    api_handler = APIHandler(api_chain, path=path, include_callback_events=True)
    return await api_handler.invoke(request, server_config=langfuse_config)