message: use getRef instead of anonymous function
diff: @@ -67,6 +67,8 @@ export default class DatePickerWrapper extends PickerBase {
  shouldDisableDate: undefined,
  }
  + getRef = (node) => { this.wrapper = node; }
  +
  render() {
  const { date } = this.state;
  const {
  @@ -93,7 +95,7 @@ export default class DatePickerWrapper extends PickerBase {
  return (
  <ModalWrapper
  - ref={(node) => { this.wrapper = node; }}
  + ref={this.getRef}
  value={value}
  format={format}
  onClear={this.handleClear}
  