@Nullable SetupViewModel onNavigateNext(final Fragment fragment) {
		final Activity activity = fragment.getActivity();
		if (button_next.get() == R.string.button_setup_troubleshooting) {
			WebContent.view(activity, Config.URL_SETUP_TROUBLESHOOTING.get());
			return null;
		}
		final SetupViewModel result = checkManagedProvisioningPrerequisites(activity, mIncompleteSetupAcked);
		if (result != null) return result;

		startManagedProvisioning(fragment);
		return null;
	}
View model for setup fragment

Created by Oasis on 2016/4/19.
mobile/src/main/java/com/oasisfeng/island/setup/SetupViewModel.java