def METHOD_NAME(cls, parameter_set="default"):
    """Return testing parameter settings for the estimator.
    Parameters
    ----------
    parameter_set : str, default="default"
        Name of the set of test parameters to return, for use in tests. If no
        special parameters are defined for a value, will return `"default"` set.
    Returns
    -------
    params : dict or list of dict, default = {}
        Parameters to create testing instances of the class
        Each dict are parameters to construct an "interesting" test instance, i.e.,
        `MyClass(**params)` or `MyClass(**params[i])` creates a valid test instance.
        `create_test_instance` uses the first (or only) dictionary in `params`
    """
    test_params = [
        {"lower_bound": None, "upper_bound": None},
        {"lower_bound": -(10**6), "upper_bound": None},
        {"lower_bound": None, "upper_bound": 10**6},
        {"lower_bound": -(10**6), "upper_bound": 10**6},
    ]
    return test_params