code: protected boolean handleOption (String arg, String nextArg, OptionArgument handler)
          throws YarrgParseException
      {
          checkState(handler != null, "No such option '" + arg + "'");
          if (handler instanceof ValueOptionArgument) {
              checkState(nextArg != null, "'" + arg + "' requires a value following it");
              parse(nextArg, handler);
              return true;
          } else if (handler instanceof HelpArgument) {
              throw new YarrgHelpException(_usage, _detail);
          } else {
              parse("true", handler);
              return false;
          }
      }
docs: Adds the value of arg and possibly nextArg to the parser for handler.
  
  @param nextArg - The argument following this one, or null if there isn't one.
  @return if nextArg was consumed by handling this option.