docs: private void setVersion(final Future<Void> aFuture) {
          final StringBuilder specNote = new StringBuilder();
          final String ptVersion = LOGGER.getMessage(MessageCodes.PT_011, PT_VERSION_NUM);
          final String urlString = LOGGER.getMessage(MessageCodes.PT_012);
  
          specNote.append(ptVersion).append(System.lineSeparator()).append(urlString);
  
          if (LOGGER.isDebugEnabled()) {
              LOGGER.debug(MessageCodes.PT_DEBUG_005, myPath);
          }
  
          myFileSystem.writeFile(getVersionFilePath(), Buffer.buffer(specNote.toString()), result -> {
              if (result.succeeded()) {
                  if (hasPrefix()) {
                      setPrefix(aFuture);
                  } else {
                      aFuture.complete();
                  }
              } else {
                  aFuture.fail(result.cause());
              }
          });
      }