function readURI(node) {
  const s = getAllTextContent(node, false).trim();
  let baseURI = node.baseURI;
  if (!baseURI || baseURI == 'about:blank') {
    baseURI = window.location.href;
  }
  if (baseURI) {
    const url = new URL(s, baseURI);
    return url.href;
  }
  return s;
}
@param {Node} node Node.
@return {string} URI.