code: private void writeCompletionFile() {
          File completionFile = getCompletionFile();
          try {
              if (completionFile.createNewFile()) {
                  log.info("successfully created completion marker file: {}",
                           completionFile.getAbsolutePath());
              } else {
                  log.warn("completion marker file unexpectably exists already " +
                           "- something may be amiss: {}",
                           completionFile.getAbsolutePath());
  
              }
          } catch (IOException e) {
              log.error("Unable to create the completion file {}: {}",
                        completionFile.getAbsolutePath(),
                        e.getMessage());
          }
      }
docs: Writes zero length file to the work directory to mark the completion of a run.