public function testCountMessages()
 {
     $count1 = $this->queue->count();
     // Queue list command
     $command1 = ['command' => 'list'];
     $this->queue->push($command1);
     $count2 = $this->queue->count();
     $this->assertEquals($count1 + 1, $count2, 'countMessages retrieve added message');
 }