message: Implemented BarTitleViewIOS by function component.
diff: @@ -3,18 +3,9 @@ import { requireNativeComponent, Platform, StyleSheet } from 'react-native';
  const NVBarTitleView = requireNativeComponent<any>('NVBarTitleView', null)
  -class BarTitleView extends React.Component {
  - render() {
  - const { style } = this.props as any
  - return (
  - <NVBarTitleView
  - {...this.props}
  - style={[styles.barTitleView, style]}>
  - {this.props.children}
  - </NVBarTitleView>
  +const BarTitleView = ({style, ...props}) => (
  + <NVBarTitleView {...props} style={[styles.barTitleView, style]}/>
  )
  - }
  -}
  const styles = StyleSheet.create({
  barTitleView: {
  