// wrapper over CLASS casted to interface,
// resulting object has ONE interface
// ALL target methods are wrapped
WrapperProxettaBuilder builder = proxetta.builder(calc.getClass(), Calc.class, ".CalcImpl2");
Class<Calc> calc2Class = builder.define();
Calc calc2 = calc2Class.newInstance();
builder.injectTargetIntoWrapper(calc, calc2);