code: public Observable<Page<Certificate>> listNextAsync(final String nextPageLink, final CertificateListNextOptions certificateListNextOptions) {
          return listNextWithServiceResponseAsync(nextPageLink, certificateListNextOptions)
              .map(new Func1<ServiceResponseWithHeaders<Page<Certificate>, CertificateListHeaders>, Page<Certificate>>() {
                  @Override
                  public Page<Certificate> call(ServiceResponseWithHeaders<Page<Certificate>, CertificateListHeaders> response) {
                      return response.body();
                  }
              });
      }
docs: Lists all of the certificates that have been added to the specified account.
  
  @param nextPageLink The NextLink from the previous successful call to List operation.
  @param certificateListNextOptions Additional parameters for the operation
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;Certificate&gt; object