def __init__(self, app, config, facebook_class=Facebook):
        self.app = app
        self.config = config
        self.facebook_class = facebook_class
see issue 218
dataset/ETHPy150Open benadida/helios-server/helios_auth/auth_systems/facebookclient/wsgi.py/FacebookWSGIMiddleware.__init__--crossover with--dataset/ETHPy150Open djc/couchdb-python/couchdb/tests/design.py/DesignTestCase.test_sync_many