def text(self):
        """Get indent text as \t or string of spaces
        """
        if self.useTabs:
            return '\t'
        else:
            return ' ' * self.width
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)