def load_from_openmmlab(filename, map_location=None):
    """load checkpoint through the file path prefixed with open-mmlab or
    openmmlab.

    Args:
        filename (str): checkpoint file path with open-mmlab or
        openmmlab prefix
        map_location (str, optional): Same as :func:`torch.load`.
          Default: None

    Returns:
        dict or OrderedDict: The loaded checkpoint.
    """

    model_urls = get_external_models()
    prefix_str = 'open-mmlab://'
    if filename.startswith(prefix_str):
        model_name = filename[13:]
    else:
        model_name = filename[12:]
        prefix_str = 'openmmlab://'

    deprecated_urls = get_deprecated_model_names()
    if model_name in deprecated_urls:
        warnings.warn(f'{prefix_str}{model_name} is deprecated in favor '
                      f'of {prefix_str}{deprecated_urls[model_name]}')
        model_name = deprecated_urls[model_name]
    model_url = model_urls[model_name]
    # check if is url
    if model_url.startswith(('http://', 'https://')):
        checkpoint = load_from_http(model_url, map_location=map_location)
    else:
        filename = osp.join(_get_mmcv_home(), model_url)
        if not osp.isfile(filename):
            raise IOError(f'{filename} is not a checkpoint file')
        checkpoint = torch.load(filename, map_location=map_location)
    return checkpoint
load checkpoint through the file path prefixed with open-mmlab or
    openmmlab.

    Args:
        filename (str): checkpoint file path with open-mmlab or
        openmmlab prefix
        map_location (str, optional): Same as :func:`torch.load`.
          Default: None

    Returns:
        dict or OrderedDict: The loaded checkpoint.
    
ControlNet-v1-1-nightly/annotator/uniformer/mmcv/runner/checkpoint.py