code: def convenience_calc_probs(self, params):
          
          orig_nest_coefs, betas = self.convenience_split_params(params)
          natural_nest_coefs = nc.naturalize_nest_coefs(orig_nest_coefs)
  
          args = [natural_nest_coefs,
                  betas,
                  self.design,
                  self.rows_to_obs,
                  self.rows_to_nests]
          kwargs = {"chosen_row_to_obs": self.chosen_row_to_obs,
                    "return_type": "long_and_chosen_probs"}
  
          probability_results = general_calc_probabilities(*args, **kwargs)
  
          return probability_results
docs: Calculates the probabilities of the chosen alternative, and the long
          format probabilities for this model and dataset.