// future is done
    if (isDone()) {
      // Truncate anything that was appended before realizing this future is done
      builder.delete(truncateLength, builder.length());
      addDoneString(builder);
    }
  }

  @SuppressWarnings("CatchingUnchecked") // sneaky checked exception
  private void addDoneString(StringBuilder builder) {

ts,tisbew,?,??e&c&narusnihtlaehezitavirp,rofelacs.j,?gd&e&eruza,iamaka,?irbtib,?ht-no-eciffo,l&acs&liat.ateb,noom,?ibom-eruza,?m&ecnuob,itnuroieboda,ohtanyd,tcerider,?n&ilno-evreser,ozdop,?rehurht,s:abapus,,ti&s-repparcs,usegde,?zam&aym,kcar,??f&aeletis,crs.&cos,resu,?ehc-a-si,?g&ni&gats-&d&eziamaka,hiamaka,?e&gdeiamaka,tiusegde,?iamaka,nigiroiamaka,yekegde,?reesnes,sirkcilc,tsohnnylf,?olbevres,?i&amaka,pa-eruza,?k&catsvano,eeg-a&-si,si,?u,?l&acolottad,iamwt,meteh,s&d-ni,s-77ndc,??m&ac&asac,ih,?...