ttribute values in a node document, given an attribute type.
   *
   * @param {string} search: A string to filter attribute value on.
   * @param {string} attributeType: The type of attribute we want to retrieve the values.
   * @param {Element} node: The element we want to get possible attributes for. This will
   *        be used to get the document where the search is happening.
   * @returns {Array<string>} An array of strings
   */
  async getAttributesInOwnerDocument(search, attributeType, node) {
    if (!attributeType) {
      throw new Error("`type` should not be empty");
    }

    if (!search) {
      return [];
    }

    const lcFilter = search.toLowerCase();

    // If the new filter includes the string that was used on our last trip to the server,
    // we can filter the cached results instead of calling the server again.
    if (
      this._attributesCache &&
      this._attributesCache.has(attributeType) &&
      search.startsWith(this._attributesCache.get(attributeType).search)
    ) {
      const cachedResults = this._attributesCache
        .get(attributeType)
        .results.filter(item => item.toLowerCase().startsWith(lcFilter));
      this.emitForTests(
        "getAttributesInOwnerDocument-cache-hit",
        cachedResults
      );
      return cachedResults;
    }

    const results = await super.getAttributesInOwnerDocument(
      search,
      attributeType,
      node
    );
    this._attributesCache.set(attributeType, { search, results });
    return results;
  }

  _clearAttributesCache() {
    this._attributesCache.clear();
  }
}

registerFront(PageStyleFront);
PK