堆栈溢出，这一段代码会互相调用导致StackOverflowException

[djnwzs]

    public static bool operator ==(HotKey key1, HotKey key2)
    {
        return key1 != null && key2 != null && key1.Equals(key2);
    }

    public static bool operator !=(HotKey key1, HotKey key2)
    {
        return !(key1 == key2);
    }