public void Consume() { Type[] types = new Type[] { typeof (int), typeof (string) }; IPortReceive[] ports = new IPortReceive[] { new Port<int>(), new Port<string> () }; int count = 1; Handler<ICollection[]> handler = (cols) => {}; var mig = new MultipleItemGather (types, ports, count, handler); try { mig.Consume (new PortElement<int> (10)); Assert.Fail ("#1"); } catch (InvalidOperationException) {} }