def METHOD_NAME(self, exog):
    '''return frozen scipy.stats distribution with mu at estimated prediction
    '''
    if not hasattr(self, "result"):
        # TODO: why would this be ValueError instead of AttributeError?
        # TODO: Why even make this a Model attribute in the first place?
        #  It belongs on the Results class
        raise ValueError
    else:
        result = self.result
        params = result.params
        mu = np.exp(np.dot(exog, params))
        return stats.poisson(mu, loc=0)