code: public HttpStub createRule() {
          if (this.responder != null) {
              return new HttpStub(predicates, this.responder);
          }
          
          final List<StubResponse> res = new ArrayList<StubResponse>(this.stubResponses.size());
          for(final MutableStubResponse msr: this.stubResponses) {
              res.add(msr.toStubResponse());
          }
          
          return new HttpStub(predicates, new StaticResponder(res));
      }
docs: Creates a {@link HttpStub} instance from this Stubbing instance.
  Must be called once this stubbing has been finished.
  @return {@link HttpStub} instance configured using values from this stubbing