System.Linq.Expressions.ConstantCheck.IsNull C# (CSharp) Метод

        internal static bool IsNull(Expression e)
        {
            switch (e.NodeType)
            {
                case ExpressionType.Constant:
                    return ((ConstantExpression)e).Value == null;
                case ExpressionType.Default:
                    return e.Type.IsNullableOrReferenceType();
            }

            return false;
        }