add Hand and NullCollections

BearOnline/cards/collections/_nullcollection.py

@@ -0,0 +1,26 @@
+from ._deck import Deck
+
+
+class NullDeck(Deck):
+    def __init__(self):
+        """Initializes an empty deck that can never contain cards.  Useful as a placeholder to prevent cards from being played to a space.
+        """
+        super().__init__([], 0)
+
+    def __add__(self, *args, **kwargs):
+        raise NotImplementedError("Cards can not be added to a NullDeck")
+
+    def __iadd__(self, *args, **kwargs):
+        raise NotImplementedError("Cards can not be added to a NullDeck")
+
+    def append(self, *args, **kwargs):
+        raise NotImplementedError("Cards can not be added to a NullDeck")
+
+    def appendleft(self, *args, **kwargs):
+        raise NotImplementedError("Cards can not be added to a NullDeck")
+
+    def extend(self, *args, **kwargs):
+        raise NotImplementedError("Cards can not be added to a NullDeck")
+
+    def extendleft(self, *args, **kwargs):
+        raise NotImplementedError("Cards can not be added to a NullDeck")