gistfile1.php

<?php

class CachedClassMetadata extends ClassMetadata
{
 private $filemtime;

 public function setFilemtime($filemtime)
 {
  $this->filemtime = $filemtime;
 }

 public function isValid($filemtime)
 {
  return $this->filemtime == $fimemtime;
 }

}