public function loadSchema()
    {
         $return = false; // Net_LDAP2 will load schema from LDAP
         if (file_exists($this->config['path'])) {
             $cache_maxage = filemtime($this->config['path']) + $this->config['max_age'];
             if (time() <= $cache_maxage || $this->config['max_age'] == 0) {
                 $return = unserialize(file_get_contents($this->config['path']));
             }
         }
         return $return;
    }