def timestamp_metadata(self):
    with open(self.bc_path, 'rb') as file:
        data = file.read(12)
    mtime = int(os.stat(self.source_path).st_mtime)
    compare = struct.pack('<4sll', importlib.util.MAGIC_NUMBER, 0, mtime)
    return (data, compare)
def timestamp_metadata(self):
    with open(self.bc_path, 'rb') as file:
        data = file.read(12)
    mtime = int(os.stat(self.source_path).st_mtime)
    compare = struct.pack('<4sll', importlib.util.MAGIC_NUMBER, 0, mtime)
    return (data, compare)