'Test the style 4 of time_format.'

def test_style_4(self):

    self.assertEqual(utils.time_format(0, 4), '0    seconds')
    self.assertEqual(utils.time_format(28, 4), '28    seconds')
    self.assertEqual(utils.time_format(92, 4), 'a    minute')
    self.assertEqual(utils.time_format(300, 4), '5    minutes')
    self.assertEqual(utils.time_format(660, 4), '11    minutes')
    self.assertEqual(utils.time_format(3600, 4), 'an    hour')
    self.assertEqual(utils.time_format(3725, 4), 'an    hour')
    self.assertEqual(utils.time_format(86350, 4), '23    hours')
    self.assertEqual(utils.time_format(86800, 4), 'a    day')
    self.assertEqual(utils.time_format(130800, 4), 'a    day')
    self.assertEqual(utils.time_format(530800, 4), '6    days')
    self.assertEqual(utils.time_format(3030800, 4), 'a    month')
    self.assertEqual(utils.time_format(7030800, 4), '2    months')
    self.assertEqual(utils.time_format(40030800, 4), 'a    year')
    self.assertEqual(utils.time_format(90030800, 4), '2    years')
