def importHelper(self, struct):
        m = StrStrHashMap()
        keysAndValues = struct.get(self.__field)
        for i in range(0, len(keysAndValues), 2):
            m[keysAndValues[i]] = keysAndValues[i+1]
        return m
def get_config(self):
    config = super().get_config()
    config['masked_tokens'] = tuple(self._masked_tokens)
    return config