def fix_checkbox(params):
    """
    Replace param_checkbox with param-indexed.
    """
    pol_params = {}
    # drop checkbox parameters.
    for param, data in params.items():
        if param.endswith("checkbox"):
            base_param = param.split("_checkbox")[0]
            pol_params[f"{base_param}-indexed"] = data
        else:
            pol_params[param] = data

    return pol_params