protected CrudViewModelBase(string entityEndpoint)
 {
     DeleteCommand       = new AsyncCommandBase(Delete);
     UpdateCommand       = new AsyncCommandBase(Update);
     CreateCommand       = new AsyncCommandBase(Create);
     CreateModeCommand   = new Command(CreateCommandMethod);
     CreateEntity        = new T1();
     Entities            = new ObservableCollection <T>();
     WebApiEntityService = new WebApiEntityService <T, T1>(entityEndpoint);
     Initialization      = Initialize();
 }
        protected override async Task InitializeData()
        {
            var crewService   = new WebApiEntityService <Crew, EditableCrewFields>("crews");
            var flightService = new WebApiEntityService <Flight, EditableFlightFields>("flights");
            var planeService  = new WebApiEntityService <Plane, EditablePlaneFields>("planes");

            Planes  = new ObservableCollection <Plane>(await planeService.GetAll());
            Crews   = new ObservableCollection <Crew>(await crewService.GetAll());
            Flights = new ObservableCollection <Flight>(await flightService.GetAll());
            OnPropertyChanged(nameof(SelectedEntity));
        }