def test_same_letters(self):
self.assertEqual(letter_counter('a'), {'a': 1})
self.assertEqual(letter_counter('aa'), {'a': 2})
def test_distinct_letters(self):
self.assertEqual(letter_counter('ab'), {'a': 1, 'b': 1})
self.assertEqual(letter_counter('abab'), {'a': 2, 'b': 2})
self.assertEqual(letter_counter('aaacbbb'), {'a': 3, 'b': 3, 'c': 1})
self.assertEqual(letter_counter('hablaaahami'), {'a': 5, 'b': 1, 'h': 2, 'm': 1, 'l': 1, 'i': 1})
self.assertEqual(letter_counter('kacsa'), {'a': 2, 'k': 1, 'c': 1, 's': 1 })
def test_if_exist(self):
self.assertEqual(letter_counter(''), {})
def test_different_letters(self):
self.assertEqual(letter_counter('b'), {'b': 1})