How to use the unittest2.loader.TestLoader function in unittest2

def main(sdk_path, test_path):
    sys.path.insert(0, sdk_path)
    import dev_appserver
    dev_appserver.fix_sys_path()
    suite = unittest2.loader.TestLoader().discover(test_path)
    test_result = unittest2.TextTestRunner(verbosity=2, buffer=True, failfast=True).run(suite)
    if not test_result.wasSuccessful():
        sys.exit(1)

def main(sdk_path, test_paths):
    if 'lib' not in sys.path:
        sys.path.insert(0, 'lib')

    sys.path.insert(0, sdk_path)
    import dev_appserver
    dev_appserver.fix_sys_path()

    suites = unittest2.TestSuite()
    for test_path in test_paths:
        suite = None
        # tests/ directory
        if os.path.isdir(test_path):
            suite = unittest2.loader.TestLoader().discover(test_path)
        # test_file.py
        elif os.path.isfile(test_path):
            test_path, test_file = test_path.rsplit(os.path.sep, 1)
            suite = unittest2.loader.TestLoader().discover(test_path, test_file)
        # tests.module.TestCase
        elif '/' not in test_path and '.' in test_path:
            suite = unittest2.loader.TestLoader().loadTestsFromName(test_path)

        if suite is not None:
            suites.addTest(suite)

    unittest2.TextTestRunner(verbosity=2).run(suites)

import dev_appserver
    dev_appserver.fix_sys_path()

    suites = unittest2.TestSuite()
    for test_path in test_paths:
        suite = None
        # tests/ directory
        if os.path.isdir(test_path):
            suite = unittest2.loader.TestLoader().discover(test_path)
        # test_file.py
        elif os.path.isfile(test_path):
            test_path, test_file = test_path.rsplit(os.path.sep, 1)
            suite = unittest2.loader.TestLoader().discover(test_path, test_file)
        # tests.module.TestCase
        elif '/' not in test_path and '.' in test_path:
            suite = unittest2.loader.TestLoader().loadTestsFromName(test_path)

        if suite is not None:
            suites.addTest(suite)

    unittest2.TextTestRunner(verbosity=2).run(suites)

sys.path.insert(0, 'lib')

    sys.path.insert(0, sdk_path)
    import dev_appserver
    dev_appserver.fix_sys_path()

    suites = unittest2.TestSuite()
    for test_path in test_paths:
        suite = None
        # tests/ directory
        if os.path.isdir(test_path):
            suite = unittest2.loader.TestLoader().discover(test_path)
        # test_file.py
        elif os.path.isfile(test_path):
            test_path, test_file = test_path.rsplit(os.path.sep, 1)
            suite = unittest2.loader.TestLoader().discover(test_path, test_file)
        # tests.module.TestCase
        elif '/' not in test_path and '.' in test_path:
            suite = unittest2.loader.TestLoader().loadTestsFromName(test_path)

        if suite is not None:
            suites.addTest(suite)

    unittest2.TextTestRunner(verbosity=2).run(suites)

def main(sdk_path, test_pattern):
    logging.disable(logging.WARNING)

    start_time = time.time()

    os.environ['IS_TBA_TEST'] = "true"

    sys.path.insert(0, sdk_path)
    import dev_appserver
    dev_appserver.fix_sys_path()

    # Set up custom django template filters
    from google.appengine.ext.webapp import template
    template.register_template_library('common.my_filters')

    suites = unittest2.loader.TestLoader().discover("tests", test_pattern)

    fail = False
    total_tests_run = 0
    if MULTITHREAD:
        proc_lock = multiprocessing.Lock()
        fail_count = multiprocessing.Value('i', 0)
        total_run = multiprocessing.Value('i', 0)
        pool = multiprocessing.Pool(MAX_JOBS, initializer=proc_init, initargs=(proc_lock, fail_count, total_run,))
        pool.map(run_suite, suites)
        pool.close()
        pool.join()

        fail = fail_count.value > 0
        total_tests_run = total_run.value
    else:
        result_queue = multiprocessing.Queue()

sys.path.insert(0, sdk_path)
  import dev_appserver
  dev_appserver.fix_sys_path()

  # Set up datastore so we can test on meaningful data.
  t = testbed.Testbed()
  t.setup_env(True, application_id='dev~openmobiledata')
  t.activate()
  t.init_datastore_v3_stub(True, TEST_DATASTORE, False)
  t.init_memcache_stub()

  # Get correct Django version.
  from google.appengine.dist import use_library
  use_library('django', '1.2')

  suite = unittest2.loader.TestLoader().discover(test_path,
                                                 pattern='*_test.py')
  unittest2.TextTestRunner(verbosity=2).run(suite)

  t.deactivate()

"""Register search service"""
    from google.appengine.api import apiproxy_stub_map
    from google.appengine.api.search import simple_search_stub
    apiproxy_stub_map.apiproxy = apiproxy_stub_map.APIProxyStubMap()
    apiproxy_stub_map.apiproxy.RegisterStub('search',
            simple_search_stub.SearchServiceStub())
    """Register memcache service"""
    from google.appengine.api.memcache import memcache_stub
    apiproxy_stub_map.apiproxy.RegisterStub('memcache',
            memcache_stub.MemcacheServiceStub())
    """Register user service"""
    from google.appengine.api import user_service_stub
    apiproxy_stub_map.apiproxy.RegisterStub('user',
            user_service_stub.UserServiceStub())

    suite = unittest2.loader.TestLoader().discover(test_path)
    unittest2.TextTestRunner(verbosity=2).run(suite)

def main(gae_lib_root, start_dir):
    """Try to load Google App Engine SDK and then to run any tests found with 
    unittest2 discovery feature.
    
    If a test fail, it will exit with a status code of 1.

    """
    setup_gae(gae_lib_root)
    suite = unittest.loader.TestLoader().discover(start_dir)
    results = unittest.TextTestRunner(verbosity=2, buffer=True).run(suite)
    if not results.wasSuccessful():
        sys.exit(1)