def METHOD_NAME(
    project_name, asset_doc=None, asset_id=None, fields=None
):
    """Return linked assets based on passed asset document.
    One of asset document or asset id must be passed.
    Args:
        project_name (str): Name of project where to look for queried entities.
        asset_doc (Dict[str, Any]): Asset document from database.
        asset_id (Union[ObjectId, str]): Asset id. Can be used instead of
            asset document.
        fields (Iterable[str]): Fields that should be returned. All fields are
            returned if 'None' is passed.
    Returns:
        List[Dict[str, Any]]: Asset documents of input links for passed
            asset doc.
    """
    link_ids = get_linked_asset_ids(project_name, asset_doc, asset_id)
    if not link_ids:
        return []
    return list(get_assets(project_name, asset_ids=link_ids, fields=fields))