如何忽略操作员重载

Question

我正在实现IComparible与

public int CompareTo(RangeEx range)
{
    if (range == null)
                return 1;
// more stuff
}

public static bool operator ==(RangeEx x, RangeEx y) { return x.CompareTo(y) == 0; }

问题是“ if（range == null）”调用运算符重载。如何通过不调用重载来检查null？