<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _main_thread_terminated(self):
 """Callback that attempts to send pending logs before termination."""

        if not self.is_alive:
            return

        if not self._queue.empty():
            print(
                "Program shutting down, attempting to send %d queued log "
                "entries to Stackdriver Logging..." % (self._queue.qsize(),),
                file=sys.stderr,
            )

        if self.stop(self._grace_period):
            print("Sent all pending logs.", file=sys.stderr)
        else:
            print(
                "Failed to send %d pending logs." % (self._queue.qsize(),),
                file=sys.stderr,
            )