public void Evaluate()
{
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 {
ITask res = null;
mig.Evaluate (new PortElement<int> (10), ref res);
Assert.Fail ("#1");
} catch (InvalidOperationException) {}
}