docs: private String generateCopyUidResponseCode(ImapSessionFolder currentMailbox,
                                                 List<Long> copiedUidsFrom, List<Long> copiedUidsTo) {
          StringBuilder copyuidResponseCode = new StringBuilder("COPYUID").append(SP).
                  append(currentMailbox.getUidValidity()).append(SP).
                  append(IdRange.uidsToRangeString(copiedUidsFrom)).append(SP).
                  append(IdRange.uidsToRangeString(copiedUidsTo));
  
          return copyuidResponseCode.toString();
      }