connectWillAppear: WrapperComponent should save reference

class WrapperComponent extends Component {
  constructor(props) {
    super(props);
    this.refHandler = this.refHandler.bind(this);
  }

  refHandler(c) {
    this.instance = c.getWrappedInstance();
  }

  render() {
    return (
      <WrappedComponent
        {...this.props}
        ref={this.refHandler}
      />
    );
  }
}