docs: public Observable<List<CertificateEmailInner>> retrieveCertificateEmailHistoryAsync(String resourceGroupName, String name) {
          return retrieveCertificateEmailHistoryWithServiceResponseAsync(resourceGroupName, name).map(new Func1<ServiceResponse<List<CertificateEmailInner>>, List<CertificateEmailInner>>() {
              @Override
              public List<CertificateEmailInner> call(ServiceResponse<List<CertificateEmailInner>> response) {
                  return response.body();
              }
          });
      }