code: @Override
    public int compareTo(ID o) {
      JobID that = (JobID)o;
      int jtComp = this.jtIdentifier.compareTo(that.jtIdentifier);
      if(jtComp == 0) {
        return this.id - that.id;
      }
      else return jtComp;
    }
docs: Compare JobIds by first jtIdentifiers, then by job numbers