public function get_bits(string $id_usr_opt, $id_parent = false, bool $with_config = true): array
  {
    $c = $this->class_cfg['arch']['user_options_bits'];
    $t = $this;
    $where = [
      $c['id_user_option'] => $id_usr_opt
    ];
    if ( is_null($id_parent) || \bbn\str::is_uid($id_parent) ){
      $where[$c['id_parent']] = $id_parent;
    }
    if (
      \bbn\str::is_uid($id_usr_opt) &&
      ($bits = $this->db->rselect_all($this->class_cfg['tables']['user_options_bits'], [], $where, [$c['num'] => 'ASC']))
    ){
      if ( !empty($with_config) ){
        return array_map(function($b) use($t){
          return $t->explode_bit_cfg($b);
        }, $bits);
      }
      return $bits;
    }
    return [];
  }