docs: def _calc_BB_prior(self, theta_0):
          """Generate a prior for the BB model
  
          Parameters
          ----------
          theta_0 : array-like, shape=(n_strata,)
              array of oracle probabilities (probability of a "1" label)
              for each stratum. This is just a guess.
  
          Returns
          -------
          alpha_0 : numpy.ndarray, shape=(n_strata,)
              "alpha" hyperparameters for an ensemble of Beta-distributed rvs
  
          beta_0 : numpy.ndarray, shape=(n_strata,)
              "beta" hyperparameters for an ensemble of Beta-distributed rvs
          """
          #: Easy vars
          prior_strength = self.prior_strength
  
          #weighted_strength = self.weights * strength
          n_strata = len(theta_0)
          weighted_strength = prior_strength / n_strata
          alpha_0 = theta_0 * weighted_strength
          beta_0 = (1 - theta_0) * weighted_strength
          return alpha_0, beta_0