public void OnSmth(Expression<Func<object>> expr)
        {
            MemberExpression body = expr.Body as MemberExpression;
            if (body == null)
            {
                UnaryExpression ubody = (UnaryExpression) expr.Body;
                body = ubody.Operand as MemberExpression;
            }

            if (body == null)
                throw new ArgumentException("Invalid property expression","expr");

            string name = body.Member.Name;

        }