def _get_network_vswitch_map_by_port_id(self, port_id):
        """Get the vswitch name for the received port id."""
        for network_id, vswitch in six.iteritems(self._network_vswitch_map):
            if port_id in vswitch['ports']:
                return (network_id, vswitch)

        # If the port was not found, just return (None, None)
        return (None, None)
Get the vswitch name for the received port id.