String newClassName = cls.getName() + "Factory";
ASMHelper helper = new ASMHelper();
ClassWriter cw = helper.createClassWriter();
MethodVisitor mv;
cw.visit(Opcodes.V1_6, Opcodes.ACC_PUBLIC + Opcodes.ACC_SUPER,
ASMHelper.periodToSlashes(newClassName), null, "java/lang/Object", null);
cw.visitSource(cls.getSimpleName() + "Factory" + ".java", null);
mv = cw.visitMethod(Opcodes.ACC_PUBLIC, "<init>", "()V", null, null);