public function testAll()
 {
     $pool = new \Jenner\SimpleFork\ParallelPool(new ParallelPoolTestRunnable(), 10);
     $pool->start();
     $this->assertEquals(10, $pool->aliveCount());
     sleep(4);
     $this->assertEquals(0, $pool->aliveCount());
     $pool->keep();
     $this->assertEquals(10, $pool->count());
     $this->assertEquals(10, $pool->aliveCount());
     $pool->wait(true);
 }