code: def gone_assignments(self):
          '''
              Returns the list of past assignments the user did not submit for
              before the hard deadline.
          '''
          # Include only assignments with past hard deadline
          qs = Assignment.objects.filter(hard_deadline__lt=timezone.now())
          # Include only assignments from courses this user is registered for
          qs = qs.filter(course__in=self.user_courses())
          # Include only assignments this user has no submission for
          return qs.order_by('-hard_deadline'f gone_assignments(self):
          '''
              Returns the list of past assignments the user did not submit for
              before the hard deadline.
          '''
          # Include only assignments with past hard deadline
          qs = Assignment.objects.filter(hard_deadline__lt=timezone.now())
          # Include only assignments from courses this user is registered for
          qs = qs.filter(course__in=self.user_courses())
          # Include only assignments this user has no submission for
          return qs.order_by('-hard_deadline')
docs: Returns the list of past assignments the user did not submit for
              before the hard deadline.