docs: public MailInAdapterResult findMail(Mail mail) {
      int indexPosition = Collections.binarySearch(items, mail, MailComparator.INSTANCE);
      boolean containsMail = false;
      Mail found = null;
      if (indexPosition < 0) {
        indexPosition = ~indexPosition;
      } else {
        found = items.get(indexPosition);
        if (found.getId() == mail.getId()) {
          containsMail = true;
        } else {
          containsMail = false;
          found = null;
        }
      }
  
      return new MailInAdapterResult(containsMail, found, indexPosition);
    }