readNetworkLinks(source) {
    const networkLinks = [];
    if (typeof source === 'string') {
      const doc = parse(source);
      extend(networkLinks, this.readNetworkLinksFromDocument(doc));
    } else if (isDocument(source)) {
      extend(
        networkLinks,
        this.readNetworkLinksFromDocument(/** @type {Document} */ (source)),
      );
    } else {
      extend(
        networkLinks,
        this.readNetworkLinksFromNode(/** @type {Element} */ (source)),
      );
    }
    return networkLinks;
  }
Read the network links of the KML.

@param {Document|Element|string} source Source.
@return {Array<Object>} Network links.
@api