old_contents: import doctest
  import unittest
  
  import luigi.task
  
  
  class TaskTest(unittest.TestCase):
  	
  	def test_tasks_doctest(self):
  		doctest.testmod(luigi.task)
  
new_contents: import doctest
  import unittest
  
  import luigi.task
  import luigi
  from datetime import datetime, timedelta
  
  
  class DummyTask(luigi.Task):
  
      param = luigi.Parameter()
      bool_param = luigi.BooleanParameter()
      int_param = luigi.IntParameter()
      float_param = luigi.FloatParameter()
      date_param = luigi.DateParameter()
      datehour_param = luigi.DateHourParameter()
      timedelta_param = luigi.TimeDeltaParameter()
      list_param = luigi.Parameter(is_list=True)
  
  
  class TaskTest(unittest.TestCase):
  
      def test_tasks_doctest(self):
          doctest.testmod(luigi.task)
  
      def test_task_to_str_to_task(self):
          params = dict(
              param='test',
              bool_param=True,
              int_param=666,
              float_param=123.456,
              date_param=datetime(2014, 9, 13).date(),
              datehour_param=datetime(2014, 9, 13, 9),
              timedelta_param=timedelta(44),  # doesn't support seconds
              list_param=['in', 'flames'])
  
          original = DummyTask(**params)
          other = DummyTask.from_str_params(original.to_str_params(), {})
          self.assertEqual(original, other)
  
  
  if __name__ == '__main__':
      unittest.main()
  
subject: Add test for task to str params conversion