# File lib/dep_selector/gecode_wrapper.rb, line 137
    def mark_preferred_to_be_at_latest(package_id, weight)
      raise "Gecode internal failure (mark_preferred_to_be_at_latest)" if gecode_problem.nil?
      check_package_id(package_id, "package_id")
      Dep_gecode.MarkPackagePreferredToBeAtLatest(gecode_problem, package_id, weight);
    end