public override bool Walk(BinaryExpression node) { if (base.Walk(node)) { switch (node.Operator) { case PythonOperator.In: return(Save(node.OperatorIndex, true, "in")); case PythonOperator.NotIn: return(Save(node.OperatorIndex, true, "not") && Save(node.GetIndexOfSecondOp(_ast), true, "in")); case PythonOperator.Is: case PythonOperator.IsNot: return(Save(node.OperatorIndex, true, "is") && Save(node.GetIndexOfSecondOp(_ast), true, "not")); } return(true); } return(false); }