old_contents: import sys
  from brainstorming.serializers import BrainstormingSerializer
  from brainstorming.tests.factories import BrainstormingFactory
  import unittest2
  
  
  class BrainstormingTestCase(unittest2.TestCase):
      def test_write_only_email_field(self):
          object = BrainstormingFactory()
          serializer = BrainstormingSerializer(object)
          self.assertNotIn('creatorEmail', serializer.data)
  
new_contents: import sys
  from brainstorming.serializers import BrainstormingSerializer
  from brainstorming.tests.factories import BrainstormingFactory
  import unittest2
  
  
  class BrainstormingTestCase(unittest2.TestCase):
      def test_write_only_email_field(self):
          obj = BrainstormingFactory.build()
          serializer = BrainstormingSerializer(obj)
          self.assertNotIn('creatorEmail', serializer.data)
  
subject: use factory's build method to create non-persistent objects