code: public void printUsage(OutputStream out, boolean showHidden) {
          printUsage(new PrintWriter(new OutputStreamWriter(out, UTF_8)), showHidden);
      }
docs: Print the option usage list. Essentially printed as a list of options
  with the description indented where it overflows the available line
  width.
  
  @param out The output stream.
  @param showHidden Whether to show hidden options.