Refs #24919 -- Made test models serializable for migrations.

tests/queryset_pickle/models.py

@@ -1,6 +1,7 @@
 import datetime
 
 from django.db import DJANGO_VERSION_PICKLE_KEY, models
+from django.utils import six
 from django.utils.translation import ugettext_lazy as _
 
 
@@ -13,15 +14,6 @@ class Numbers(object):
     def get_static_number():
         return 2
 
-    @classmethod
-    def get_class_number(cls):
-        return 3
-
-    def get_member_number(self):
-        return 4
-
-nn = Numbers()
-
 
 class PreviousDjangoVersionQuerySet(models.QuerySet):
     def __getstate__(self):
@@ -51,11 +43,11 @@ class Event(models.Model):
 
 class Happening(models.Model):
     when = models.DateTimeField(blank=True, default=datetime.datetime.now)
-    name = models.CharField(blank=True, max_length=100, default=lambda: "test")
+    name = models.CharField(blank=True, max_length=100, default="test")
     number1 = models.IntegerField(blank=True, default=standalone_number)
-    number2 = models.IntegerField(blank=True, default=Numbers.get_static_number)
-    number3 = models.IntegerField(blank=True, default=Numbers.get_class_number)
-    number4 = models.IntegerField(blank=True, default=nn.get_member_number)
+    if six.PY3:
+        # default serializable on Python 3 only
+        number2 = models.IntegerField(blank=True, default=Numbers.get_static_number)
 
 
 class Container(object):