original_string: public function getVolumeFeed($location = null)
      {
          if ($location == null) {
              $uri = self::VOLUME_FEED_URI;
          } else if ($location instanceof Zend_Gdata_Query) {
              $uri = $location->getQueryUrl();
          } else {
              $uri = $location;
          }
          return parent::getFeed($uri, 'Zend_Gdata_Books_VolumeFeed');
      }
code: public function getVolumeFeed($location = null)
      {
          if ($location == null) {
              $uri = self::VOLUME_FEED_URI;
          } else if ($location instanceof Zend_Gdata_Query) {
              $uri = $location->getQueryUrl();
          } else {
              $uri = $location;
          }
          return parent::getFeed($uri, 'Zend_Gdata_Books_VolumeFeed');
      }
code_tokens: public function getVolumeFeed ( $ location = null ) { if ( $ location == null ) { $ uri = self :: VOLUME_FEED_URI ; } else if ( $ location instanceof Zend_Gdata_Query ) { $ uri = $ location -> getQueryUrl ( ) ; } else { $ uri = $ location ; } return parent :: getFeed ( $ uri , 'Zend_Gdata_Books_VolumeFeed' ) ; }
docstring: Retrieves a feed of volumes.
  
  @param Zend_Gdata_Query|string|null $location (optional) The URL to
  query or a Zend_Gdata_Query object from which a URL can be
  determined.
  @return Zend_Gdata_Books_VolumeFeed The feed of volumes found at the
  specified URL.
docstring_tokens: Retrieves a feed of volumes .