new_contents: import devilry
  from django.test import RequestFactory, TestCase
  from django.utils import timezone
  import htmls
  import mock
  from model_mommy import mommy
  from devilry.devilry_group.views.feedbackfeed_student import StudentFeedbackFeedView
  from devilry.devilry_group.views.feedbackfeed_timeline_builder import FeedbackFeedTimelineBuilder
  from devilry.project.develop.testhelpers.corebuilder import UserBuilder2, AssignmentGroupBuilder, FeedbackSetBuilder, \
      GroupCommentBuilder
  
  
  class TestFeedbackFeedTimelineBuilder(TestCase, object):
  
      def test_get_feedbacksets_for_group(self):
          timelinebuilder = FeedbackFeedTimelineBuilder(None)
          assignment = mommy.make_recipe('devilry.apps.core.assignment_activeperiod_start')
          assignment_group = mommy.make(
              'core.AssignmentGroup',
              parentnode=assignment,
              name='dewey'
          )
          feedbackset = mommy.make(
              'devilry_group.FeedbackSet',
              group=assignment_group,
              created_datetime=timezone.now(),
              deadline_datetime=timezone.now()+timezone.timedelta(days=11)
          )
          feedbackset1 = mommy.make(
              'devilry_group.FeedbackSet',
              group=assignment_group,
              created_datetime=timezone.now(),
              deadline_datetime=timezone.now()+timezone.timedelta(days=10)
          )
  
          self.assertEquals(2, len(timelinebuilder.get_feedbacksets_for_group(assignment_group)))
subject: test class for FeedbackFeedTimelineBuilder