__getURL(path) {
      let url = path;

      if (path.indexOf('//') === -1) {
         url = this.__apiBase + path;
      }

      let newCacheBuster = 'timestamp=' + new Date().getTime();
      return url.replace(/(timestamp=\d+)/, newCacheBuster);
   }
Compute the URL to use to make a request.
@private
@param {string} path - either a URL relative to the API base or an absolute URL
@return {string} - the URL to use