code: def main(self, ignored_argv=('',)):
      
      self._install_signal_handler(signal.SIGTERM, "SIGTERM")
      if self.flags.inspect:
        logger.info('Not bringing up TensorBoard, but inspecting event files.')
        event_file = os.path.expanduser(self.flags.event_file)
        efi.inspect(self.flags.logdir, event_file, self.flags.tag)
        return 0
      if self.flags.version_tb:
        print(version.VERSION)
        return 0
      try:
        server = self._make_server()
        sys.stderr.write('TensorBoard %s at %s (Press CTRL+C to quit)\n' %
                         (version.VERSION, server.get_url()))
        sys.stderr.flush()
        self._register_info(server)
        server.serve_forever()
        return 0
      except TensorBoardServerException as e:
        logger.error(e.msg)
        sys.stderr.write('ERROR: %s\n' % e.msg)
        sys.stderr.flush()
        return -1
docs: Blocking main function for TensorBoard.
  
      This method is called by `tensorboard.main.run_main`, which is the
      standard entrypoint for the tensorboard command line program. The
      configure() method must be called first.
  
      Args:
        ignored_argv: Do not pass. Required for Abseil compatibility.
  
      Returns:
        Process exit code, i.e. 0 if successful or non-zero on failure. In
        practice, an exception will most likely be raised instead of
        returning non-zero.
  
      :rtype: int