Comparing APIs before and after Registration_refactor PR

After.java

class PushApplication extends Application {
  
    private PushRegistrar registrar;
    private PushConfig config;
    private final Registrations registrations = new Registrations();
    private static final String VARIANT_ID       = "";
    private static final String SECRET           = "";
    private static final String GCM_SENDER_ID    = "";
    private static final String UNIFIED_PUSH_URL = "";
    private static final String MY_ALIAS         = "";
  
    public void onCreate() {
        super.onCreate();
        try {
            
            config = new PushConfig(new URL(UNIFIED_PUSH_URL), GCM_SENDER_ID);
            config.setVariantID(VARIANT_ID);
            config.setSecret(SECRET);
            config.setAlias(MY_ALIAS);
            
            registrar = registrations.push("registrar", config);
            

        } catch (MalformedURLException e) {
            throw new RuntimeException(e);
        }
    }
    
    public void register() {
        registrar.register(getApplicationContext(), new MyCallback<Void>());
    }
    
    public void unregister() {
        registrar.unregister(getApplicationContext(), new MyCallback<Void>()); 
    }
    
}

Before.java

class PushApplication extends Application {
  
    private Registrar registrar;
    private PushConfig config;
    private static final String VARIANT_ID       = "";
    private static final String SECRET           = "";
    private static final String GCM_SENDER_ID    = "";
    private static final String UNIFIED_PUSH_URL = "";
    private static final String MY_ALIAS         = "";
  
  @Override
  public void onCreate() {
		super.onCreate();
		try {
			final Registrar r = new Registrar(new URL(UNIFIED_PUSH_URL));
			PushConfig config = new PushConfig(GCM_SENDER_ID);
			config.setVariantID(VARIANT_ID);
			config.setSecret(SECRET);
			config.setAlias(MY_ALIAS);
			
			r.register(getApplicationContext(), config, new Callback<Void>() {
				
				private static final long serialVersionUID = 1L;

				@Override
				public void onSuccess(Void ignore) {
					registrar  = r;
				}
				
				@Override
				public void onFailure(Exception exception) {
					Log.e(TAG, exception.getMessage(), exception);
				}
			});
		} catch (MalformedURLException e) {
			throw new RuntimeException(e);
		}
	}
}