Refs #17917 -- Added a test for pickling annotations on fields with callable defaults.

import unittest

import warnings

from django.db import models

from django.test import TestCase

from django.utils import six

from django.utils.encoding import force_text

        m2ms = pickle.loads(pickle.dumps(m2ms))

        self.assertQuerysetEqual(m2ms, [m2m], lambda x: x)

    def test_annotation_with_callable_default(self):

        # Happening.when has a callable default of datetime.datetime.now.

        qs = Happening.objects.annotate(latest_time=models.Max('when'))

        self.assert_pickles(qs)

    def test_missing_django_version_unpickling(self):

        """

        #21430 -- Verifies a warning is raised for querysets that are