code: protected void usage() {
  		String footnotes = null;
  		if (!getOptions().getCommands().isEmpty()) {
  			footnotes = "Use `" + CSLToolContext.current().getToolName() +
  					" help <command>' to read about a specific command.";
  		}
  		
  		String name = CSLToolContext.current().getToolName();
  		String usageName = getUsageName();
  		if (usageName != null && !usageName.isEmpty()) {
  			name += " " + usageName;
  		}
  		
  		String unknownArguments = OptionIntrospector.getUnknownArgumentName(
  				getClassesToIntrospect());
  		
  		OptionParser.usage(name, getUsageDescription(), getOptions(),
  				unknownArguments, footnotes, new PrintWriter(System.out, true));
  	}
docs: Prints out usage information