code: @Override
  	public void close() {
  		Iterator<Map.Entry<Path, OpenCryptoFile>> iter = openCryptoFiles.entrySet().iterator();
  		while (iter.hasNext()) {
  			Map.Entry<Path, OpenCryptoFile> entry = iter.next();
  			iter.remove(); // remove before invoking close() to avoid concurrent modification of this iterator by #close(OpenCryptoFile)
  			entry.getValue().close();
  		}
  	}
docs: Close all currently opened files by invoking {@link OpenCryptoFile#close()}.