class Key(str):
    def __hash__(self): return 1
    def __eq__(self, other): return Key.eq
    eq = False

a = Key("a")
b = Key("b")
assert hash(a) == hash(b)
assert a != b
kw = {a: 1, b: 2}

Key.eq = True
assert hash(a) == hash(b)
assert a == b
print("call with:", kw)
kw2 = dict(**kw)
print("got:", kw2)