function registerNavigationFilter(oModel) {
		const oShellNavigationInternalService = oModel.getUShellService("ShellNavigationInternal");
		if (!_mVariantIdChangeHandlers[oModel.sFlexReference]) {
			_mVariantIdChangeHandlers[oModel.sFlexReference] = handleVariantIdChangeInURL.bind(null, oModel);
			if (oShellNavigationInternalService) {
				oShellNavigationInternalService.registerNavigationFilter(_mVariantIdChangeHandlers[oModel.sFlexReference]);
			}
		}
	}
Registers navigation filter function for the ushell ShellNavigationInternal service.

@param {sap.ui.fl.variants.VariantModel} oModel - Variant Model

@private