def test_currency_changes_for_several_numbers_returns_list_in_usd_with_decimals(self):
     self.assertEqual(multiple_currency_usd([5.46, 10.23]), [6.07, 11.37])
 def usd_test_currency_changes_for_several_numbers_with_letters(self):
     self.assertEqual(multiple_currency_usd([1, 2, "a"]), "That's not a valid currency amount")
 def test_currency_changes_for_several_numbers_returns_list_in_usd(self):
     self.assertEqual(multiple_currency_usd([.9, 1.8, 2.7]), [1, 2, 3])