def test_non_callable(self):
        with pytest.raises(TypeError) as excinfo:
            event.event(123)
        excinfo.match(r"Expected string, callable or None as first argument")

        with pytest.raises(TypeError) as excinfo:
            event.event("name")([])
        excinfo.match(r"Callable must be a function \(`def`\)"
                      r" or coroutine function \(`async def`\)")
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)