def test_empty(self): self.assertEqual(format_numbers(''),'')
def test_quit(self): self.assertEqual(format_numbers('q U I t '),'quit')
def test_string_1(self): self.assertEqual(format_numbers('4 , 3, 5,7'),'4,3,5,7')
def test_empty(self): self.assertEqual(format_numbers(''), '')
def test_quit(self): self.assertEqual(format_numbers('q U I t '), 'quit')
def test_string_1(self): self.assertEqual(format_numbers('4 , 3, 5,7'), '4,3,5,7')