/**
  * Applies a translatable index to a basic query. This scope will join the index
  * table and cannot be executed more than once.
  * @param  Builder $query
  * @param  string $index
  * @param  string $value
  * @param  string $locale
  * @return Builder
  */
 public function scopeTransWhere($query, $index, $value, $locale = null)
 {
     if (!$locale) {
         $locale = $this->translatableContext;
     }
     $query->select($this->model->getTable() . '.*');
     $query->where(function ($q) use($index, $value) {
         $q->where($this->model->getTable() . '.' . $index, $value);
         $q->orWhere(function ($q) use($index, $value) {
             $q->where('rainlab_translate_indexes.item', $index)->where('rainlab_translate_indexes.value', $value);
         });
     });
     // This join will crap out if this scope executes twice, it is a known issue.
     // It should check if the join exists before applying it, this mechanism was
     // not found in Laravel. So options are block joins entirely or allow once.
     $query->leftJoin('rainlab_translate_indexes', function ($join) use($locale) {
         $join->on(Db::raw(DbDongle::cast($this->model->getQualifiedKeyName(), 'TEXT')), '=', 'rainlab_translate_indexes.model_id')->where('rainlab_translate_indexes.model_type', '=', get_class($this->model))->where('rainlab_translate_indexes.locale', '=', $locale);
     });
     return $query;
 }