public void CreateSomeCommandsWithSameKey()
{
ICommand command1 = ReactiveCommandEx.CreateWithHistoryFromObservable <Unit, Unit>(CommandKey,
(parameter, result) => Observables.Unit,
(parameter, result) => Observables.Unit,
_canExecuteSubject,
_scheduler);
Assert.Throws <ArgumentException>(() =>
{
ICommand command2 = ReactiveCommandEx.CreateWithHistoryFromObservable <Unit, Unit>(CommandKey,
(parameter, result) => Observables.Unit,
(parameter, result) => Observables.Unit,
_canExecuteSubject,
_scheduler);
});
}