def exportValue(self, vf, value):
        m = StrStrHashMap(value)
        keysAndValues = []
        for i in m.keys():
            keysAndValues.append(i)
            keysAndValues.append(m[i])
def __init__(self, masked_tokens=None, name='accuracy', dtype=None):
    self._masked_tokens = masked_tokens or []
    super().__init__(name, dtype=dtype)