langchain/callbacks/aim_callback.py/BaseMetadataCallbackHandler/get_custom_callback_meta
class BaseMetadataCallbackHandler:    def get_custom_callback_meta(self) -> Dict[str, Any]:
        return {
            "step": self.step,
            "starts": self.starts,
            "ends": self.ends,
            "errors": self.errors,
            "text_ctr": self.text_ctr,
            "chain_starts": self.chain_starts,
            "chain_ends": self.chain_ends,
            "llm_starts": self.llm_starts,
            "llm_ends": self.llm_ends,
            "llm_streams": self.llm_streams,
            "tool_starts": self.tool_starts,
            "tool_ends": self.tool_ends,
            "agent_ends": self.agent_ends,
        }