code: public function hasTags(array $tags)/*# : array */
      {
          $x = [];
          foreach ($tags as $tag) {
              if ($this->hasTag($tag)) {
                  $x[] = $tag;
              }
          }
          return $x;
      }
docs: Return array of tags existed, return empty [] if no match found
  
  @param  array $tags tags to match against
  @return array
  @access public
  @api