text:  import * as React from 'react';
  import { StyleSheet, Text, View, Image } from 'react-native';
  import WelcomeScreen from './screens/WelcomeScreen';
  import { createAppContainer, createSwitchNavigator } from 'react-navigation';
  import { createBottomTabNavigator } from 'react-navigation-tabs';
  // import { AppDrawerNavigator } from '';
  
  export default class App extends React.Component {
    render() {
      return <AppContainer/>;
    }
  }
  
  const switchNavigator = createSwitchNavigator({
    WelcomeScreen: { screen: WelcomeScreen },
    // Drawer:{screen: AppDrawerNavigator}
  });
  
  const AppContainer = createAppContainer(switchNavigator);
  