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 __add__(self, other):
        assert self.n_classes == other.n_classes, "Number of classes does not match"
        return MulticlassContingencyTable(self.table + other.table,
                                          n_classes=self.n_classes,
                                          class_names=self.class_names)