--combinePlacements (Just _) Nothing = Nothing
-- A single chromosome was used, even though no extension happened
combinePlacements (Just (packages, residuals, chromosomePackages, qm, used)) Nothing =
  Just (packages, residuals, chromosomePackages, qm, succ used)
combinePlacements (Just (packages, residuals, chromosomePackages, qm, used)) Nothing =
  Just (packages, residuals, chromosomePackages, qm, succ used)
combinePlacements (Just (packages, residuals, chromosomePackages, qm, used)) Nothing =
  Just (packages, residuals, chromosomePackages, qm, succ used)