Resque_Worker::exists PHP Method

    public static function exists($workerId)
    {
        return (bool) Resque::redis()->sismember('workers', $workerId);
    }

 public function testWorkerCanUnregister()
 {
     $worker = new Resque_Worker('*');
     $worker->registerWorker();
     $worker->unregisterWorker();
     $this->assertFalse(Resque_Worker::exists((string) $worker));
     $this->assertEquals(array(), Resque_Worker::all());
     $this->assertEquals(array(), $this->redis->smembers('resque:workers'));
 }