message: added all of the required properties
diff: @@ -7,14 +7,20 @@ import "./style.css";
  export default class GaugeMenu extends React.Component {
  static propTypes = {
  - opener: PropTypes.element
  + opener: PropTypes.element,
  + value: PropTypes.number.isRequired,
  + maxDelay: PropTypes.number.isRequired,
  + onChange: PropTypes.func.isRequired
  };
  + handleChange(value) {
  + this.props.onChange(this.props.maxDelay - value);
  + }
  render() {
  return (
  <Menu opener={this.props.opener} direction={MenuDirections.Bottom} closeOnClick={false} width={40} padding={0}>
  <div className="speed-gauge">
  <span>Fast</span>
  - <Slider vertical included={false} defaultValue={50} onChange={console.log.bind(console)} />
  + <Slider vertical included={false} min={0} max={this.props.maxDelay} value={this.props.maxDelay - this.props.value} onChange={this.handleChange.bind(this)} />
  <span>Slow</span>
  </div>
  </Menu>
  