def test_observer():
bank = Bank()
atm_registry = ATMRegistry()
atm = atm_registry.get('usd')
bank.add_atm(atm)
bank.update = mock.Mock()
atm.withdraw(100)
assert bank.update.called == True
def test_prototype():
bank = Bank()
atm_registry = ATMRegistry()
for _ in range(3):
bank.add_atm(atm_registry.get('rub'))
for _ in range(4):
bank.add_atm(atm_registry.get('usd'))
assert len(bank.atms) == 7
assert len([a for a in bank.atms if a.balance() == 1000]) == 3
assert len([a for a in bank.atms if a.balance() == 100]) == 4