_findAll(names) {
    const results = [];
    for (const tag of this._commentTags) {
      if (names.includes(tag.tagName)) results.push(tag);
    }

    if (results.length) {
      return results;
    } else {
      return null;
    }
  }
find all tags.
@param {string[]} names - tag names.
@returns {Tag[]|null} found tags.
@private