def METHOD_NAME(self, ts_extension, finder_id, finder_offset, object_typetag='halo', mode=None):
    assert object_typetag=='halo'
    return DummyTimestepData("Test string - this would contain the data for %s halo %d"%(ts_extension ,finder_id),
                             float(self._get_ts_property(ts_extension, 'time')),
                             int(self._get_ts_property(ts_extension, 'halos')),
                             finder_offset)