code: @SuppressWarnings("unchecked")
      private static void printUsage(final Exception e) {
          printVersion();
          if (e != null) {
              System.out.println(e.getMessage() + "\n");
          }
  
          HelpFormatter hf = new HelpFormatter();
  
          StringBuilder sbDivider = new StringBuilder("=");
          while (sbDivider.length() < hf.getPageWidth()) {
              sbDivider.append("=");
          }
  
          // DISPLAY SETTING
          hf.getDisplaySettings().clear();
          hf.getDisplaySettings().add(DisplaySetting.DISPLAY_GROUP_EXPANDED);
          hf.getDisplaySettings().add(DisplaySetting.DISPLAY_PARENT_CHILDREN);
  
          // USAGE SETTING
  
          hf.getFullUsageSettings().clear();
          hf.getFullUsageSettings().add(DisplaySetting.DISPLAY_PARENT_ARGUMENT);
          hf.getFullUsageSettings().add(DisplaySetting.DISPLAY_ARGUMENT_BRACKETED);
          hf.getFullUsageSettings().add(DisplaySetting.DISPLAY_PARENT_CHILDREN);
          hf.getFullUsageSettings().add(DisplaySetting.DISPLAY_GROUP_EXPANDED);
  
          hf.setDivider(sbDivider.toString());
  
          hf.setGroup(configureCommandLine());
          hf.print();
          System.exit(0);
      }
docs: Prints the JNRPE Server usage and, eventually, the error about the last
  invocation.
  
  @param e
  The last error. Can be null.