def generate_annotations_json(source_path, target_path, only_simple=False):
    # type: (str, str, bool) -> None
    """Like generate_annotations_json_string() but writes JSON to a file."""
    results = generate_annotations_json_string(source_path, only_simple=only_simple)
    with open(target_path, 'w') as f:
        json.dump(results, f, sort_keys=True, indent=4)
Like generate_annotations_json_string() but writes JSON to a file.