/**
  * Stores the fields that can be used for sorting or filtering in the
  * sort / filter objects attached to this model.
  *
  * @param array $parameters
  * @param boolean $includeNumericFilters When true numeric filter keys (0, 1, 2...) are added to the filter as well
  * @return array The $parameters minus the sort & textsearch keys
  */
 public function applyParameters(array $parameters, $includeNumericFilters = false)
 {
     if ($parameters) {
         // Altkey
         if (isset($parameters[\Gems_Model::RESPONDENT_TRACK])) {
             $id = $parameters[\Gems_Model::RESPONDENT_TRACK];
             unset($parameters[\Gems_Model::RESPONDENT_TRACK]);
             $parameters['gr2t_id_respondent_track'] = $id;
         }
         if (isset($parameters[\Gems_Model::TRACK_ID])) {
             $id = $parameters[\Gems_Model::TRACK_ID];
             unset($parameters[\Gems_Model::TRACK_ID]);
             $parameters['gtr_id_track'] = $id;
         }
         return parent::applyParameters($parameters, $includeNumericFilters);
     }
     return array();
 }