Gather metrics using codahale stuff

timer.java

    Counter failCounter = new Counter();
    Counter successCounter = new Counter();
    Timer timer = new Timer();

    @Override
    public Y transform(X x) {
        Timer.Context time = timer.time();
        try {
            Y transform = delegate.transform(x);
            successCounter.inc();
            return transform;
        } catch (Exception e) {
            failCounter.inc();
            throw e;
        } finally {
            time.stop();
        }
    }