def exportValue(self, vf, value):
        m = StrStrHashMap(value)
        keysAndValues = []
        for i in m.keys():
            keysAndValues.append(i)
            keysAndValues.append(m[i])
def get_config(self):
    config = super().get_config()
    config['masked_tokens'] = tuple(self._masked_tokens)
    return config