old_contents: import unittest
  
  from nymms import utils
  
  
  class TestBase(unittest.TestCase):
      def test_load_class_from_string(self):
          from logging import Logger
          cls = utils.load_object_from_string('logging.Logger')
          self.assertIs(cls, Logger)
  
new_contents: import unittest
  
  from nymms import utils
  from nymms.exceptions import InvalidTimeFormat
  
  
  class TestBase(unittest.TestCase):
      def test_load_class_from_string(self):
          from logging import Logger
          cls = utils.load_object_from_string('logging.Logger')
          self.assertIs(cls, Logger)
  
      def test_parse_time(self):
          base_time = 1415311935
          self.assertEqual(utils.parse_time('+60s', base_time), base_time + 60)
          self.assertEqual(utils.parse_time('+10m', base_time),
                           base_time + (60 * 10))
          self.assertEqual(utils.parse_time('+10h', base_time),
                           base_time + (60 * 60 * 10))
          self.assertEqual(utils.parse_time('-10d', base_time),
                           base_time - (10 * 60 * 60 * 24))
          with self.assertRaises(InvalidTimeFormat):
              utils.parse_time('+2000xxx')
  
subject: Add parse_time tests