public void GetConnectorsTest()
        {
            var source = new FourInOneOutExpression
                             {
                                 Connector1In = {Name = "1"},
                                 Connector2In = {Name = "2"},
                                 Connector3In = {Name = "3"},
                                 Connector4In = {Name = "4"},
                                 ConnectorOut = {Name = "5"}
                             };

            var conn = source.GetConnectors();
            var connectors = conn as IList<IConnector> ?? conn.ToList();
            Assert.IsTrue(connectors.Any(x => x.Name == "1"));
            Assert.IsTrue(connectors.Any(x => x.Name == "2"));
            Assert.IsTrue(connectors.Any(x => x.Name == "3"));
            Assert.IsTrue(connectors.Any(x => x.Name == "4"));
            Assert.IsTrue(connectors.Any(x => x.Name == "5"));
        }