Running a specific test case in Django when your app has a tests directory

The Django documentation (http://docs.djangoproject.com/en/1.3/topics/testing/#running-tests) says that you can run individual test cases by specifying them:

$ ./manage.py test animals.AnimalTestCase

This assumes that you have your tests in a tests.py file in your Django application. If this is true, then this command works like expected.

I have my tests for a Django application in a tests directory:

my_project/apps/my_app/
├── __init__.py
├── tests
│   ├── __init__.py
│   ├── field_tests.py
│   ├── storage_tests.py
├── urls.py
├── utils.py
└── views.py

The tests/__init__.py file has a suite() function:

import unittest

from my_project.apps.my_app.tests import field_tests, storage_tests

def suite():
    tests_loader = unittest.TestLoader().loadTestsFromModule
    test_suites = []
    test_suites.append(tests_loader(field_tests))
    test_suites.append(tests_loader(storage_tests))
    return unittest.TestSuite(test_suites)

To run the tests I do:

$ ./manage.py test my_app

Trying to specify an individual test case raises an exception:

$ ./manage.py test my_app.tests.storage_tests.StorageTestCase
...
ValueError: Test label 'my_app.tests.storage_tests.StorageTestCase' should be of the form app.TestCase or app.TestCase.test_method

I tried to do what the exception message said:

$ ./manage.py test my_app.StorageTestCase
...
ValueError: Test label 'my_app.StorageTestCase' does not refer to a test

How do I specify an individual test case when my tests are in multiple files?