def METHOD_NAME(period):
    """Return a multi-realization air temperature cube. This fixture is
    parameterised such that any test using it will be run with both instantaneous
    and period air temperature as an input."""
    temperature = temperature_cube(period)
    temperature = add_coordinate(
        temperature, [0, 1, 2], "realization", coord_units=1, dtype=np.int32
    )
    return temperature