Note that this Hand data structure assumes that there is only one of each card, which doesn’t work for games like pinochle that have 2 (or more) of each card (by combining multiple standard decks or by using custom decks). And the Hand constructor doesn’t check for this possibility (it ignores cards that appear more than once).
(Also, pinochle uses a nonstandard card ranking: A 10 K Q J 9, and there are no cards below a 9. So maybe it is too weird to support. 
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