def test_iadd(self, evt):
        rval = event.ReturnValue(append_events=[evt])
        rval2 = event.ReturnValue(eat=True, append_events=[evt])
        rset = event.ResultSet()

        rset += rval
        rset += rval2
        rset += None
        assert rset.eat
        assert rset.append_events == [evt, evt]
def sort(cls, dataset, by=[], reverse=False):
        cols = [dataset.get_dimension(d, strict=True).name for d in by]
        return dataset.data.sort_values(by=cols, ascending=not reverse)