def METHOD_NAME(
    self,
    *,
    n_in_dv: [float, np.ndarray],
    kappa: float,
    r_dry: [float, np.ndarray],
    rtol=default_rtol,
):
    if not isinstance(n_in_dv, np.ndarray):
        r_dry = np.array([r_dry])
        n_in_dv = np.array([n_in_dv])
    attributes = {}
    attributes["dry volume"] = self.formulae.trivia.volume(radius=r_dry)
    attributes["kappa times dry volume"] = attributes["dry volume"] * kappa
    attributes["multiplicity"] = n_in_dv
    r_wet = equilibrate_wet_radii(
        r_dry=r_dry,
        environment=self,
        kappa_times_dry_volume=attributes["kappa times dry volume"],
        rtol=rtol,
    )
    attributes["volume"] = self.formulae.trivia.volume(radius=r_wet)
    return attributes