code: def _handle_chat_event(self, event: events.ChatMessageWasReceived) -> None:
          
          for subscriber in self._chat_subscribers:
              try:
                  subscriber(event)
              except Exception:
                  LOG.exception(self._prefix_log_message(
                      f"failed to send chat event {event} to "
                      f"subscriber {subscriber}"
                  ))
docs: Not thread-safe.