/**
  * This method allows the exception to return any extra HTTP response headers.
  *
  * The headers must be returned as an array.
  *
  * @param \SabreForRainLoop\DAV\Server $server
  * @return array
  */
 public function getHTTPHeaders(\SabreForRainLoop\DAV\Server $server)
 {
     $methods = $server->getAllowedMethods($server->getRequestUri());
     return array('Allow' => strtoupper(implode(', ', $methods)));
 }