message: do not require these props
diff: @@ -5,8 +5,8 @@ import "./style.css";
  export default class ModalHeader extends React.Component {
  static propTypes = {
  - title: PropTypes.string.isRequired,
  - close: PropTypes.func.isRequired
  + title: PropTypes.string,
  + close: PropTypes.func
  };
  render() {
  return (
  