def METHOD_NAME(self):
    self.leave.channel_groups("gr")
    self.assertEqual(self.leave.build_path(), Leave.LEAVE_PATH
                     % (pnconf.subscribe_key, ","))
    self.assertEqual(self.leave.build_params_callback()({}), {
        'channel-group': 'gr',
        'pnsdk': sdk_name,
        'uuid': self.pubnub.uuid
    })
    self.assertEqual(self.leave._groups, ['gr'])