title: Firebase messaging doesn't have a default constructor
body: <pre class="lang-dart prettyprint-override"><code>import 'package:flutter/material.dart';
  import 'package:firebase_messaging/firebase_messaging.dart';
  
  import 'package:google_maps_flutter/google_maps_flutter.dart';    
  
  class PushNotificationService
  {
    final FirebaseMessaging firebaseMessaging = FirebaseMessaging();
  
    Future initialize(context) async
     {
      firebaseMessaging.configure(
        onMessage: (Map&lt;String, dynamic&gt; message) async {
          retrieveRideRequestInfo(getRideRequestId(message), context);
         },
         onLaunch: (Map&lt;String, dynamic&gt; message) async {
           retrieveRideRequestInfo(getRideRequestId(message), context);
         },
         onResume: (Map&lt;String, dynamic&gt; message) async {
          retrieveRideRequestInfo(getRideRequestId(message), context);
        },
       );
      }
  
  </code></pre>
  <p>Manifest:</p>
  <pre class="lang-xml prettyprint-override"><code>    &lt;intent-filter&gt;
          &lt;action android:name=&quot;FLUTTER_NOTIFICATION_CLICK&quot; /&gt;
          &lt;category android:name=&quot;android.intent.category.DEFAULT&quot; 
          /&gt;
      &lt;/intent-filter&gt;
  
  </code></pre>
  <p>Error: The class 'FirebaseMessaging' doesn't have a default constructor.
  Try using one of the named constructors defined in 'FirebaseMessaging'.</p>