default allows your program to
 handle pushes that aren't registered with a subscribe call. This can happen when your
 application changes its subscriptions directly through the ParseInstallation or via
 push-to-query.
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>context</CODE> - This is used to access local storage to cache the subscription, so it must currently
          be a viable context.<DD><CODE>cls</CODE> - This should be a subclass of Activity. An instance of this Activity is started when
         