public void CommandOnComplete_Test()
 {
     //Given
     bool completed = false;
     ReactiveCommand<string> command = new ReactiveCommand<string>(t => { }, _ => false, () =>
     {
         completed = true;
     });
     //When
     command.OnNext(Any.Create<string>());
     command.OnCompleted();
     //Then
     Assert.That(completed, Is.True);
 }