list[list[str]]

        :kwarg required_one_of: List of lists of terms, one of which in each list
            is required.
        :type required_one_of: list[list[str]]

        :kwarg required_if: List of lists of ``[parameter, value, [parameters]]`` where
            one of ``[parameters]`` is required if ``parameter == value``.
        :type required_if: list

        :kwarg required_by: Dictionary of parameter names that contain a list of
            parameters required by each key in the dictionary.
        :type required_by: dict[str, list[str]]
        Ú