code: public void printUsage(PrintStream ps) {
      hasListOption = false;
      if (usageSynopsis != null) {
        ps.printf("Usage: %s%n", usageSynopsis);
      }
      ps.println(usage());
      if (hasListOption) {
        ps.println();
        ps.println(LIST_HELP);
      }
    }
docs: Prints usage information to the given PrintStream. Uses the usage synopsis passed into the
  constructor, if any.
  
  @param ps where to print usage information