def test_equal_1(self):
self.assertEqual(two_by_two([
'goat', 'goat', 'rabbit', 'rabbit', 'rabbit', 'duck', 'horse',
'horse', 'swan'
]), {'goat': 2, 'horse': 2, 'rabbit': 2})
def test_equal_3(self):
self.assertEqual(two_by_two([
'dog', 'cat', 'dog', 'cat', 'beaver', 'cat'
]), {'cat': 2, 'dog': 2})
def test_false_1(self):
self.assertFalse(two_by_two([]))
def test_equal_2(self):
self.assertEqual(two_by_two(['goat']), {})
