message: added picker reference to renderButton
diff: @@ -93,7 +93,7 @@ class PickerNB extends Component {
  renderButton() {
  const onPress = () => { this._setModalVisible(true); };
  if (this.props.renderButton) {
  - return this.props.renderButton(onPress);
  + return this.props.renderButton(this, onPress);
  }
  return <Button
  style={this.props.style}
  