code: public Promise<Void> forceAndClose(boolean forceMetadata) {
  		if (!isOpen()) return Promise.ofException(FILE_CLOSED);
  		return ofBlockingRunnable(executor, () -> {
  			try {
  				channel.force(forceMetadata);
  				channel.close();
  			} catch (IOException e) {
  				throw new UncheckedException(e);
  			}
  		});
  	}
docs: Forces physical write and then closes the channel
  if the file is opened.
  
  @param forceMetadata whether or not to force metadata writes too