/**
  * helper assertion for the tests
  *
  * @param  string            $url      url to check
  * @param  vfsStreamContent  $content  content to compare
  */
 protected function assertFileTimesEqualStreamTimes($url, vfsStreamContent $content)
 {
     $this->assertEquals(filemtime($url), $content->filemtime());
     $this->assertEquals(fileatime($url), $content->fileatime());
     $this->assertEquals(filectime($url), $content->filectime());
 }