def METHOD_NAME(self, ctx: np.recarray, imts, mean, sig, tau, phi):
    """
    Compute mean, sig, tau, phi and returns the so called adjustment
    """
    self.gsim.METHOD_NAME(ctx, imts, mean, sig, tau, phi)
    adjustment = nga_west2_epistemic_adjustment(ctx.mag, ctx.rrup)
    mean[:] += self.sgn * adjustment
    return adjustment