from llama_index.callbacks import CallbackManager, LlamaDebugHandler, CBEventType
# Set up the LlamaDebugHandler
llama_debug = LlamaDebugHandler(print_trace_on_end=True)
callback_manager = CallbackManager([llama_debug])
# Create a ServiceContext with the CallbackManager
service_context = ServiceContext.from_defaults(callback_manager=callback_manager)
# Trigger the callback with a query
index = VectorStoreIndex.from_documents(docs, service_context=service_context)
query_engine = index.as_query_engine()
response = query_engine.query("What did the author do growing up?")