Optional Support for the build method

[StefanSchrass]

Often, if not always I am implementing the Builder like this:

public static final class Builder implements ValidatingBuilder {
        private Thing a;
        private Thing b;

        @Override
        public Boolean isValid() { return null != a && null != b; }

        public Builder withA(Thing a) {
            this.a = a;
            return this;
        }

        public Builder withB(Thing b) {
            this.b = b;
            return this;
        }

        public Optional<MyObject> build() {
            Optional<MyObject> myObject = Optional.empty();
            if (isValid()) {
                myObject = Optional.of(new MyObject(this));
            }

            return myObject;
        }
    }

The idea behind this is, that a resulting Object can only be instantiated if all mandatory fields are set (and further more with valid values). So I've made a very simple interface for this, but the build() method is not covered by it (the interface just lets me use [ctrl]-[i] to get the method stub).
I use the innerbuilder regularly and therefore issueing the request for supporting Optionals for the build method, because for me this would be a great feature.