public static bool IsSuited(ulong mask)
{
int cards = BitCount(mask);
uint sc = CardMask(mask, Clubs);
uint sd = CardMask(mask, Diamonds);
uint sh = CardMask(mask, Hearts);
uint ss = CardMask(mask, Spades);
return BitCount(sc) == cards || BitCount(sd) == cards ||
BitCount(sh) == cards || BitCount(ss) == cards;
}