code: def create_pg_notify_event(notif):
      
      # TODO Lookup registered events via getAllUtilitiesRegisteredFor
      #      for class mapping.
      if notif.channel not in _CHANNEL_MAPPER:
          cls = _CHANNEL_MAPPER[None]
      else:
          cls = _CHANNEL_MAPPER[notif.channel]
      return cls(notif)
docs: A factory for creating a Postgres Notification Event
      (an object inheriting from `cnxpublishing.events.PGNotifyEvent`)
      given `notif`, a `psycopg2.extensions.Notify` object.