async execute(url, method, body = undefined) {
    console.log('API: ', url, method, body);
    if(typeof body === 'object')
      body = JSON.stringify(body);
    let headers = this.getHeaders();
    return await fetch(url, {
      headers,
      method,
      body,
      mode: 'no-cors',
      redirect: 'follow'
   });
 }

componentDidMount() {
    console.log('AuthCallback componentDidMount()');
    if (/access_token|id_token|error/.test(this.props.location.hash)) {
      Auth.handleAuthentication(this.props.location.hash);
    }
  }