public function addFilterToPreparedQuery(array $preparedQuery)
    {
        /* If filter criteria exists for this class, prepare it and merge
         * over the existing query.
         *
         * @todo Consider recursive merging in case the filter criteria and
         * prepared query both contain top-level $and/$or operators.
         */
        if ($filterCriteria = $this->dm->getFilterCollection()->getFilterCriteria($this->class)) {
            $preparedQuery = $this->cm->merge($preparedQuery, $this->prepareQueryOrNewObj($filterCriteria));
        }

        return $preparedQuery;
    }