text: import React from 'react'
  import {
      StyleSheet,
      View,
      Text,
  } from 'react-native'
  
  export default class ChatScreen extends React.Component {
      static navigationOptions = ({ navigation }) => ({
          title: `Chat with ${navigation.state.params.user}`,
      })
  
      render() {
          const { params } = this.props.navigation.state
  
          return (
              <View style={styles.container}>
                  <Text>Chat with {params.user}</Text>
              </View>
          )
      }
  }
  
  const styles = StyleSheet.create({
      container: {
          padding: 10
      }
  })
  