  import datetime
  
  from django.db import models
  from django.core.exceptions import ImproperlyConfigured, ValidationError
  from django.utils.encoding import smart_text
  from django.utils.translation import ugettext_lazy as _
  from django.utils import timezone
  from django.contrib.admin.util import (get_model_from_relation,
      reverse_field_path, get_limit_choices_to_from_path, prepare_lookup_value)
  from django.contrib.admin.options import IncorrectLookupParameters
 
</s> remove         self.assertEqual(list(queryset), [john])
 </s> add         self.assertEqual(list(queryset), [self.john]) </s> remove         self.assertEqual(list(queryset), [jack, john])
 </s> add         self.assertEqual(list(queryset), [self.jack, self.john]) </s> remove         dev = Department.objects.create(code='DEV', description='Development')
        design = Department.objects.create(code='DSN', description='Design')
        john = Employee.objects.create(name='John Blue', department=dev)
        jack = Employee.objects.create(name='Jack Red', department=design)

 </s> add 
from django.utils.encoding import smart_text, force_text
  import datetime
  
  from django.db import models
  from django.core.exceptions import ImproperlyConfigured, ValidationError
from django.utils.encoding import smart_text, force_text
  from django.utils.translation import ugettext_lazy as _
  from django.utils import timezone
  from django.contrib.admin.util import (get_model_from_relation,
      reverse_field_path, get_limit_choices_to_from_path, prepare_lookup_value)
  from django.contrib.admin.options import IncorrectLookupParameters
keep keep keep keep replace keep keep keep keep keep
 Fixed #19318 -- Ensured that the admin's SimpleListFilter options can be displayed as selected even if the lookup's first element is not a string. 
django/contrib/admin/filters.py