langchain/callbacks/tracers/stdout.py/ConsoleCallbackHandler/_on_chain_end
class ConsoleCallbackHandler:    def _on_chain_end(self, run: Run) -> None:
        crumbs = self.get_breadcrumbs(run)
        print(
            f"{get_colored_text('[chain/end]', color='blue')} "
            + get_bolded_text(
                f"[{crumbs}] [{elapsed(run)}] Exiting Chain run with output:\n"
            )
            + f"{try_json_stringify(run.outputs, '[outputs]')}"
        )