@RubyLevelMethod(name = "sprintf", module = true)
 public static RubyValue sprintf(RubyValue receiver, RubyArray args) {
   String fmt = args.get(0).toStr();
   ByteArrayOutputStream baos = new ByteArrayOutputStream();
   PrintStream ps = new PrintStream(baos);
   ps.printf(fmt, RubyKernelModule.buildFormatArg(args, 1));
   ps.flush();
   ps.close();
   return ObjectFactory.createString(baos.toString());
 }
 @RubyLevelMethod(name = "printf", module = true)
 public static RubyValue printf(RubyValue receiver, RubyArray args) {
   String fmt = args.get(0).toStr();
   System.out.printf(fmt, RubyKernelModule.buildFormatArg(args, 1));
   return RubyConstant.QNIL;
 }