Args:
            prior: Prior object, or float, or None.
            type (string): 'intercept, 'fixed', or 'random'.

def _prepare_prior(self, prior, _type):
        '''
        Args:
            prior: Prior object, or float, or None.
            type (string): 'intercept, 'fixed', or 'random'.
        '''

        if prior is None and not self.auto_scale:
            prior = self.default_priors.get(term=_type + '_flat')

        if isinstance(prior, Prior):
            prior._auto_scale = False
        else:
            _scale = prior
            prior = self.default_priors.get(term=_type)
            prior.scale = _scale
            if prior.scale is not None:
                prior._auto_scale = False
        return prior