def test_return_coins(self):
vendmachine = VendingMachine()
# check that the coin return is empty
self.assertEqual(vendmachine.check_coin_return(), [])
# insert coins
my_coins = [self.quarter, self.quarter, self.dime]
for coin in my_coins:
vendmachine.insert_coin(coin)
vendmachine.return_coins()
change = vendmachine.take_out_coins_from_coin_return()
self.assertEqual(self.count_change(my_coins), self.count_change(change))
# check that the coin return is empty again
self.assertEqual(vendmachine.check_coin_return(), [])
