RsBundle  Diff

                let aggr = self.minorants[i].split_off(self.params.max_bundle_size-2);
                let aggr_sum = aggr.iter().map(|m| m.multiplier).sum();
                let (aggr_mins, aggr_primals) : (Vec<_>, Vec<_>) = aggr.into_iter().map(|m| {
                    (m.index, m.primal.unwrap())
                }).unzip();
                let (aggr_min, aggr_coeffs) = try!(self.master.aggregate(i, &aggr_mins));
                // append aggregated minorant
                debug_assert_eq!(aggr_coeffs.len(), aggr_primals.len());
                self.minorants[i].push(MinorantInfo{
                self.minorants[i].push(MinorantInfo {
                    index: aggr_min,
                    multiplier: aggr_sum,
                    primal: Some(self.problem.aggregate_primals(&aggr_coeffs, aggr_primals)),
                    primal: Some(self.problem.aggregate_primals(
                       aggr_coeffs.into_iter().zip(aggr_primals.into_iter()).collect())),
                });
            }
        }
        Ok(())
    }

    /// Perform a descent step.