次のコードは警告が出ます。何行目が原因？#cureapp_quiz をつけてtweetしよう！

cureapp_quiz.js

 1 import React from 'react'
 2 import { AppRegistry, StyleSheet, Text, View } from 'react-native'
 3 const styles = StyleSheet.create({
 4   container: {
 5     flex: 1,
 6     justifyContent: 'center',
 7     alignItems: 'center',
 8     color: '#000000',
 9     backgroundColor: '#F5FCFF',
10   },
11   text: {
12     fontSize: 20,
13     textAlign: 'center',
14     margin: 10,
15   },
16 })
17 export default function Quiz() {
18   return (
19     <View style={styles.container}>
20       <Text style={styles.text}>Welcome to React Native!</Text>
21     </View>
22   )
23 }
24 AppRegistry.registerComponent('quiz', () => Quiz)