'Assert that the supplied ``directory`` has all the sub-directories
required by ``LoopbackBlockDeviceAPI``.'

def assertDirectoryStructure(self, directory):

    attached_directory = directory.child(LoopbackBlockDeviceAPI._attached_directory_name)
    unattached_directory = directory.child(LoopbackBlockDeviceAPI._unattached_directory_name)
    LoopbackBlockDeviceAPI.from_path(root_path=directory.path, compute_instance_id=random_name(self))
    self.assertTrue((True, True), (attached_directory.exists(), unattached_directory.exists()))
