docs: public static Path createTempFolder(String prefix) throws IOException {
  		Path parent = Paths.get(System.getProperty("java.io.tmpdir"));
  		if (!Files.isDirectory(parent)) {
  			throw new IOException("java.io.tmpdir points to a non-existing folder: " + parent);
  		}
  		Path ret = null;
  		int i = 0;
  		do {
  			ret = parent.resolve(Objects.requireNonNull(prefix)+Long.toHexString(System.currentTimeMillis())+"-"+Integer.toHexString(RND.nextInt()));
  			i++;
  			if (i>=100) {
  				throw new IOException("Failed to create temporary folder.");
  			}
  		} while (!ret.toFile().mkdirs());
  		return ret;
  	}