code: public Observable<Page<PolicySetDefinitionInner>> listBuiltInAsync() {
          return listBuiltInWithServiceResponseAsync()
              .map(new Func1<ServiceResponse<Page<PolicySetDefinitionInner>>, Page<PolicySetDefinitionInner>>() {
                  @Override
                  public Page<PolicySetDefinitionInner> call(ServiceResponse<Page<PolicySetDefinitionInner>> response) {
                      return response.body();
                  }
              });
      }
docs: Retrieves built-in policy set definitions.
  This operation retrieves a list of all the built-in policy set definitions.
  
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;PolicySetDefinitionInner&gt; object