System.Data.Select.IsOperatorIn C# (CSharp) Method

        private bool IsOperatorIn(ExpressionNode enode)
        {
            BinaryNode bnode = (enode as BinaryNode);
            if (null != bnode)
            {
                if (Operators.In == bnode._op ||
                    IsOperatorIn(bnode._right) ||
                    IsOperatorIn(bnode._left))
                {
                    return true;
                }
            }
            return false;
        }