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 testDeviceWrapper(self):
    wrapper_type = rnn_cell_wrapper_v2.DeviceWrapper
    x = array_ops.zeros([1, 3])
    m = array_ops.zeros([1, 3])
    cell = rnn_cell_impl.GRUCell(3)
    wrapped_cell = wrapper_type(cell, "/cpu:0")
    children = wrapped_cell._trackable_children()
    wrapped_cell.get_config()  # Should not throw an error
    self.assertIn("cell", children)
    self.assertIs(children["cell"], cell)

    outputs, _ = wrapped_cell(x, m)
    self.assertIn("cpu:0", outputs.device.lower())