/**
  * Lookup a user by username
  *
  * @param string $userName
  * @return array GalleryStatus a status code
  *               GalleryUser a user
  */
 function fetchUserByUserName($userName = null)
 {
     MyOOS_CoreApi::requireOnce('modules/core/classes/helpers/GalleryUserHelper_medium.class');
     return GalleryUserHelper_medium::fetchUserByUserName($userName);
 }