def METHOD_NAME():
    '''Test the _cma_operator method.'''
    meta_arg = ColumnwiseOperatorArgMetadata("GH_REAL", "GH_WRITE", "W0", "W1")
    metadata = LFRicKernelMetadata(
        operates_on="cell_column", meta_args=[meta_arg])
    cls = call_method("_cma_operator", meta_arg, metadata)
    assert len(cls._info) == 1
    # pylint: disable=unsubscriptable-object
    assert cls._info[0] == 0
    assert cls._index == 8