src/transformers/models/owlvit/convert_owlvit_original_flax_to_hf.py/flatten_nested_dict
def flatten_nested_dict(params, parent_key="", sep="/"):
    items = []

    for k, v in params.items():
        new_key = parent_key + sep + k if parent_key else k

        if isinstance(v, collections.MutableMapping):
            items.extend(flatten_nested_dict(v, new_key, sep=sep).items())
        else:
            items.append((new_key, v))
    return dict(items)