/**
  * Add column specific filters.
  */
 private function addColumnFilters()
 {
     foreach ($this->columns as $i => $column) {
         if (static::$versionTransformer->isColumnSearched($i)) {
             $this->builder->where(new raw($this->getRawColumnQuery($column)), 'like', '%' . static::$versionTransformer->getColumnSearchValue($i) . '%');
         }
     }
 }