public void Get_ShouldCallAccept(
			Mock<IObservableViewModelVisitor> visitor,
			IBindable parent,
			ISchedulers schedulers,
			Mock<IObservableViewModelBuilder> ovmBuilder,
			Mock<IObservableViewModel> ovm
			)
		{
			//arrange
			Action<IObservableViewModel> action = null;
			var sut = new ObservableViewModelBuilderProvider(() => schedulers, (a, scheduler, arg3) =>
			{
				action = a;
				return ovmBuilder.Object;
			});
			sut.AddVisitor(visitor.Object);

			//act
			sut.Get("test");
			action(ovm.Object);

			//assert
			ovm.Verify(o => o.Accept(visitor.Object));
		}
		public void CopyVisitors_ShouldCallAddVisitor(
		  ObservableViewModelBuilderProvider sut,
		  IObservableViewModelVisitor[] visitors,
		  Mock<IObservableViewModelBuilderProvider> other)
		{
			//arrange
			foreach (var ovmVisitor in visitors)
			{
				var v = ovmVisitor;
				sut.AddVisitor(ovmVisitor);
				other.Setup(c => c.AddVisitor(v)).Verifiable();
			}

			//act
			sut.CopyVisitors(other.Object);

			//assert
			other.Verify();
		}