def get_dir_from_zipfile(zip_file, fallback=None):
    """Return the name of the root folder in a zip file.

    :param zip_file: a :class:`zipfile.ZipFile` instance.
    :param fallback: if `None`, the name of the zip file is used. This is
        returned if the zip file contains more than one top-level directory,
        or none at all.
    """
    fallback = fallback or zip_file.filename
    directories = [name for name in zip_file.namelist() if name.endswith("/")
                   and len(PurePath(name).parts) == 1]
    return fallback if len(directories) > 1 else directories[0]
def test_attach_detach_volume_to_instance(self):
        """Test attaching and detaching volume to instance"""
        # Create a server
        server = self.create_server()
        # Volume is attached and detached successfully from an instance
        self.volumes_client.attach_volume(self.volume['id'],
                                          instance_uuid=server['id'],
                                          mountpoint='/dev/%s' %
                                          CONF.compute.volume_device_name)
        waiters.wait_for_volume_resource_status(self.volumes_client,
                                                self.volume['id'], 'in-use')
        self.volumes_client.detach_volume(self.volume['id'])
        waiters.wait_for_volume_resource_status(self.volumes_client,
                                                self.volume['id'], 'available')