public ApplicationKey getDefaultApplicationKey() {
        final MeshModel meshModel = getSelectedModel().getValue();
        if (meshModel != null && !meshModel.getBoundAppKeyIndexes().isEmpty()) {
            return getNetworkLiveData().getAppKeys().get(meshModel.getBoundAppKeyIndexes().get(0));
        }
        return null;
    }
Generic View Model class for {@link ConfigurationServerActivity},{@link ConfigurationClientActivity},
{@link GenericOnOffServerActivity}, {@link GenericLevelServerActivity}, {@link VendorModelActivity},
{@link GenericModelConfigurationActivity}
app/src/main/java/no/nordicsemi/android/nrfmesh/viewmodels/ModelConfigurationViewModel.java