public static ExhibitListState ReduceFetchExhibitListResultAction(ExhibitListState state, FetchExhibitListResultAction action) =>
 new ExhibitListState(
     isLoading: false,
     exhibits: action.Exhibits
     );
 public static ExhibitListState ReduceFetchExhibitListAction(ExhibitListState state, FetchExhibitListAction action) =>
 new ExhibitListState(
     isLoading: true,
     exhibits: null);