title: Undefined is not an object (evaluating 'context.uiTheme.toolbar' ) ('react-native-material-ui')
body: <p>I am trying to use <a href="https://github.com/xotahal/react-native-material-ui" rel="nofollow noreferrer">react-native-material-ui</a> library's toolbar. But I keep getting one error or another in the process. I have been stuck on this for a long time now. 
  My <code>index.android.js</code> looks like this:</p>
  
  <pre><code>import React, { Component } from 'react';
  import { StyleSheet,AppRegistry, View } from 'react-native';
  import { Toolbar } from './node_modules/react-native-material-ui';
  
  
  const styles = StyleSheet.create({
  pageContainer: {
      flex: 1,
  },
  });
  
  
  export default class Reminder_react extends Component {
     render() {
      return (
          &lt;View style={styles.pageContainer}&gt;
              &lt;Toolbar leftElement="arrow-back" centerElement="Icon Toggle" /&gt;
  
          &lt;/View&gt;
      );
     }
  }
  AppRegistry.registerComponent('Reminder_react', () =&gt; Reminder_react);
  </code></pre>
  
  <p>I get no error on the terminal but the phone screen lights up like red light district. This is the error.</p>
  
  <p><a href="https://i.stack.imgur.com/ruhnq.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ruhnq.png" alt="react native error stack"></a></p>