def METHOD_NAME(data_merged, plus_labels, minus_labels, suffixes):
    """
    Test behavior of DataSet.stack_anomalous()
    """
    if suffixes is None:
        result = data_merged.stack_anomalous(plus_labels, minus_labels)
    else:
        result = data_merged.stack_anomalous(plus_labels, minus_labels, suffixes)
    if plus_labels is None:
        if suffixes is not None:
            plus_labels = [l for l in data_merged.columns if l.endswith(suffixes[0])]
        else:
            plus_labels = [l for l in data_merged.columns if l.endswith("(+)")]
    elif isinstance(plus_labels, str):
        plus_labels = [plus_labels]
    assert len(result.columns) == (len(data_merged.columns) - len(plus_labels))
    centrics = data_merged.label_centrics()["CENTRIC"]
    assert len(result) == (2 * (~centrics).sum()) + centrics.sum()
    assert result.spacegroup.xhm() == data_merged.spacegroup.xhm()