import coreapi

client = coreapi.Client()
schema = client.get('https://my-service.url/docs/:443')

    def transition(self, link, decoders, params=None, link_ancestors=None, force_codec=False):
        # ...
        settings = session.merge_environment_settings(request.url, None, None, None, None)
        response = session.send(request, **settings)
        result = _decode_result(response, decoders, force_codec)
        # ...