'Smoothing method 6:
Interpolates the maximum likelihood estimate of the precision *p_n* with
a prior estimate *pi0*. The prior is estimated by assuming that the ratio
between pn and pnâ1 will be the same as that between pnâ1 and pnâ2.'

def method7(self, p_n, references, hypothesis, hyp_len, *args, **kwargs):

    p_n = self.method4(p_n, references, hypothesis, hyp_len)
    p_n = self.method5(p_n, references, hypothesis, hyp_len)
    return p_n
