code: public PathImpl createTempFile(String prefix, String suffix) throws IOException
    {
      if (prefix == null || prefix.length () == 0)
        prefix = "t";
  
      if (suffix == null)
        suffix = ".tmp";
  
      synchronized (LOCK) {
        for (int i = 0; i < 32768; i++) {
          int r = Math.abs((int) RandomUtil.getRandomLong());
          PathImpl file = lookup(prefix + r + suffix);
  
          if (file.createNewFile())
            return file;
        }
      }
  
      throw new IOException("cannot create temp file");
    }
docs: Creates a unique temporary file as a child of this directory.
  
  @param prefix filename prefix
  @param suffix filename suffix, defaults to .tmp
  @return Path to the new file.