title: error 'android.content.pm.ApplicationInfo android.content.Context.getApplicationInfo()' on a null object reference when notify notification Android
body: <p>so, i was trying to run my app and it should be show the notification after the first run. But then, it gave me an error like this:</p>
  
  <pre><code>java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.pm.ApplicationInfo android.content.Context.getApplicationInfo()' on a null object reference
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.app.Notification$Builder.&lt;init&gt;(Notification.java:1951)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.support.v4.app.NotificationCompatApi21$Builder.&lt;init&gt;(NotificationCompatApi21.java:68)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.support.v4.app.NotificationCompat$NotificationCompatImplApi21.build(NotificationCompat.java:759)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.support.v4.app.NotificationCompat$Builder.build(NotificationCompat.java:1559)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at apps.skripsi.petvac.navigationmenu.MainMenu.createButtonNotification(MainMenu.java:383)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at apps.skripsi.petvac.navigationmenu.MainMenu$DataBinatangOperation.onPostExecute(MainMenu.java:235)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at apps.skripsi.petvac.navigationmenu.MainMenu$DataBinatangOperation.onPostExecute(MainMenu.java:145)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.os.AsyncTask.finish(AsyncTask.java:632)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.os.AsyncTask.access$600(AsyncTask.java:177)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:645)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:102)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:135)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:5253)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:372)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:900)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:695)
  </code></pre>
  
  <p>and here's my code for showing the notification</p>
  
  <pre><code>public void createButtonNotification(Context context, String title, String content, String idb, String idv) {
      // Prepare intent which is triggered if the  notification button is pressed
  
  
      Intent intent = new Intent(getActivity(), MainPetInformation.class);
      intent.putExtra("IDBIN", idb);
      intent.putExtra("IDVAK", idv);
  
  
      Uri uri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
  
      int IntID = Integer.valueOf(idb);
  
      PendingIntent IntentAccept = PendingIntent.getActivity(getActivity(), IntID, intent, 0);
  
      PendingIntent IntentCancel = PendingIntent.getActivity(getActivity(), IntID, intent, 0);
      IntentCancel.cancel();
  
  
      // Building the notifcation
      NotificationCompat.Builder nBuilder = new NotificationCompat.Builder(context)
              .setSmallIcon(R.drawable.logo) // notification icon
              .setContentTitle(title) // notification title
              .setContentText(content)
              .setSound(uri)// content text
              .addAction(R.drawable.accept, "Accept", IntentAccept) // accept notification button
              .addAction(R.drawable.cancel, "Cancel", IntentCancel); // cancel notification button
  
  
      mNotificationManager.notify(IntID, nBuilder.build());
  
  
  }
  </code></pre>
  
  <p>the error stated it occured on this line:</p>
  
  <pre><code>mNotificationManager.notify(IntID, nBuilder.build());
  </code></pre>
  
  <p>please help:(</p>