def METHOD_NAME(self, i_s):
    """
    A private function to obtain the standard variables which
    can be derived from the current in the electrode.
    Parameters
    ----------
    i_s : :class:`pybamm.Symbol`
        The current in the electrode.
    Returns
    -------
    variables : dict
        The variables which can be derived from the current in the
        electrode.
    """
    Domain = self.domain.capitalize()
    variables = {
        f"{Domain} electrode current density [A.m-2]": i_s,
    }
    return variables