public function useFields($fields)
    {
        if (is_string($fields)) {
            $fields = explode(',', $fields);
        }
        $this->fields = $fields;

        return $this;
    }
public function useFields($fields)
    {
        if (is_string($fields)) {
            $fields = explode(',', $fields);
        }
        $this->fields = $fields;

        return $this;
    }
public function useFields ( $ fields ) { if ( is_string ( $ fields ) ) { $ fields = explode ( ',' , $ fields ) ; } $ this -> fields = $ fields ; return $ this ; }
Set fields on which filtering will be done.

@param string|array $fields

@return QuickSearch $this
Set fields on which filtering will be done .