def METHOD_NAME(self):
    # season categorisations work for non-standard seasons?
    cube = self.cube
    time_coord = self.time_coord
    seasons = ["djfm", "amjj", "ason"]
    ccat.add_season(cube, time_coord, name="seasons", seasons=seasons)
    ccat.add_season_number(
        cube, time_coord, name="season_numbers", seasons=seasons
    )
    ccat.add_season_year(
        cube, time_coord, name="season_years", seasons=seasons
    )
    self.assertCML(cube, ("categorisation", "customcheck.cml"))