code: def get_gpubsub_publisher(config, metrics, changes_channel, **kw):
      
      builder = gpubsub_publisher.GPubsubPublisherBuilder(
          config, metrics, changes_channel, **kw)
      return builder.build_publisher()
docs: Get a GPubsubPublisher client.
  
      A factory function that validates configuration, creates an auth
      and pubsub API client, and returns a Google Pub/Sub Publisher
      provider.
  
      Args:
          config (dict): Google Cloud Pub/Sub-related configuration.
          metrics (obj): :interface:`IMetricRelay` implementation.
          changes_channel (asyncio.Queue): Queue to publish message to
              make corrections to Cloud DNS.
          kw (dict): Additional keyword arguments to pass to the
              Publisher.
      Returns:
          A :class:`GPubsubPublisher` instance.