def test_too_long(self):
     self.assertFalse(is_phone_number('12345678901'))
 def test_incorrect_period_placement(self):
     self.assertFalse(is_phone_number('123 . 4567 . 890'))
 def test_letters(self):
     self.assertFalse(is_phone_number('123-456-78A9'))
 def test_too_short(self):
     self.assertFalse(is_phone_number('123456789'))
 def test_incorrect_dash_placement(self):
     self.assertFalse(is_phone_number('20-2762-1401'))
 def test_periods(self):
     self.assertTrue(is_phone_number('202 . 762 . 1401'))
 def test_parenthesis_with_space(self):
     self.assertTrue(is_phone_number('(202) 762-1401'))
 def test_dashes(self):
     self.assertTrue(is_phone_number('202-762-1401'))
 def test_no_punctuation(self):
     self.assertTrue(is_phone_number("8885557777"))