code: public static Func1<DocumentFragment<Mutation>, Boolean> getMapResultFnForSubdocMutationToBoolean() {
          return new Func1<DocumentFragment<Mutation>, Boolean>() {
              @Override
              public Boolean call(DocumentFragment<Mutation> documentFragment) {
                  ResponseStatus status = documentFragment.status(0);
                  if (status == ResponseStatus.SUCCESS) {
                      return true;
                  } else {
                      throw new CouchbaseException(status.toString());
                  }
              }
          };
      }
docs: Creates anonymous function for mapping document fragment result to boolean
  
  @return anonymous function