readName(source) {
    if (!source) {
      return undefined;
    }
    if (typeof source === 'string') {
      const doc = parse(source);
      return this.readNameFromDocument(doc);
    }
    if (isDocument(source)) {
      return this.readNameFromDocument(/** @type {Document} */ (source));
    }
    return this.readNameFromNode(/** @type {Element} */ (source));
  }
Read the name of the KML.

@param {Document|Element|string} source Source.
@return {string|undefined} Name.
@api