docs: public UnusedStubbings getUnusedStubbings(Iterable<Object> mocks) {
          Set<Stubbing> stubbings = AllInvocationsFinder.findStubbings(mocks);
  
          List<Stubbing> unused = filter(stubbings, new Filter<Stubbing>() {
              public boolean isOut(Stubbing s) {
                  return !UnusedStubbingReporting.shouldBeReported(s);
              }
          });
  
          return new UnusedStubbings(unused);
      }