Return the number of configs to keep for an iteration and iteration bracket.

        This is just util function around `get_n_config_to_keep`

def get_n_config_to_keep_for_iteration(self, iteration, bracket_iteration):
        """Return the number of configs to keep for an iteration and iteration bracket.

        This is just util function around `get_n_config_to_keep`
        """
        bracket = self.get_bracket(iteration=iteration)
        if bracket_iteration == bracket + 1:
            # End of loop `for bracket_iteration in range(bracket + 1):`
            return 0

        n_configs = self.get_n_configs(bracket=bracket)
        return self.get_n_config_to_keep(
            n_suggestions=n_configs, bracket_iteration=bracket_iteration)