code: private static String getReplacement(SedArguments args)
     {
        if (args.isReplacementSet())
        {
           return args.getReplacement();
        }
        if (args.isString2Set())
        {
           return args.getString2();
        }
        return "";
     }
docs: Returns the replacement operand from args, either called "replacement" or
  "string2". If none of the two is set, an empty string is returned.
  
  @param args
  the args with operand values
  @return the replacement argument from "replacement" or "string2" or an
  empty string of none of the two operands is set