public function testDestroyStorage()
 {
     $file = self::DIR . "/test.sync";
     $storage = new StorageFile($file);
     $shared = new SharedMemory($storage);
     $shared->hello = 'world';
     $this->assertTrue(file_exists($file));
     $shared->destroyStorage();
     $this->assertFalse(file_exists($file));
     $shared->hello = 'world';
     $this->assertTrue(file_exists($file));
     $shared->destroyStorage();
     $this->assertFalse(file_exists($file));
 }