我真的不明白我的代码中有什么问题，有人可以帮助我吗？

我的代码：

import React from 'react';
import { StyleSheet, Text, View, Button } from 'react-native';
import {createStackNavigator} from 'react-navigation-stack';
import { createAppContainer } from 'react-navigation';


const MainNavigator = createStackNavigator({
  Home: {screen: () => HomeScreen},
  Profile: {screen: () => ProfileScreen},
},
{
  initialRouteName : 'RouteNameOne',
}
);

const App = createAppContainer(MainNavigator);

class HomeScreen extends React.Component {
  static navigationOptions = {
    title: 'Welcome',
  };
  render() {
    const {navigate} = this.props.navigation;
    return (
      <Button
        title="Go to Jane's profile"
        onPress={() => navigate('Profile', {name: 'Jane'})}
      />
    );
  }
}

class ProfileScreen extends React.Component {
  static navigationOptions = {
    title: 'Welcome',
  };
  render() {
    const {navigate} = this.props.navigation;
    return (
      <Button
        title="Go to Home"
        onPress={() => navigate('Home', {name: 'Jane'})}
      />
    );
  }
}



export default App;