code: public function getItemHrefIndex()
      {
          if (isset($this->state[self::VAR_HREF_INDEX])) {
              $table = $this->state[self::VAR_HREF_INDEX];
          } else {
              $table = [];
          }
          return $table;
      }
docs: Loads the table that maps the items identifiers to item reference
  Fallback index in case of the delivery was compiled without the index of item href
  @return array