def test_case_with_three_numbers(self):
"""
test the case with the number 111
there is only one combination: '111'
"""
result = telephone_word_combos('111')
self.assertEqual(result,['111'])
def test_case_with_max_number_mutables(self):
"""
test the case with the number 222-2222
should yeild a result with 3**7 combinations
"""
result = telephone_word_combos('2222222')
self.assertEqual(len(result), 3**7)
def test_case_with_two_mutables(self):
"""
test the case with the number 111-1123
should yeild '11111[ABC][DEF]', 9 combinations
"""
result = telephone_word_combos('1111123')
self.assertEqual(len(result), 9)
def test_case_with_no_ones_or_zeros(self):
"""
test the case with the number 111-1111
should yield one combination: '1111111'
"""
result = telephone_word_combos('1111111')
self.assertEqual(result, ['1111111'])
def test_case_with_only_one_mutable(self):
"""
test the case with the number 111-1112
should yeild '111111[ABC]'
"""
result = telephone_word_combos('1111112')
self.assertEqual(len(result), 3)
self.assertIn('111111A', result)
self.assertIn('111111B', result)
self.assertIn('111111C', result)
