code: public Observable<Page<CertificateIssuerItem>> getCertificateIssuersAsync(final String vaultBaseUrl, final Integer maxresults) {
          return getCertificateIssuersWithServiceResponseAsync(vaultBaseUrl, maxresults)
              .map(new Func1<ServiceResponse<Page<CertificateIssuerItem>>, Page<CertificateIssuerItem>>() {
                  @Override
                  public Page<CertificateIssuerItem> call(ServiceResponse<Page<CertificateIssuerItem>> response) {
                      return response.body();
                  }
              });
      }
docs: List certificate issuers for a specified key vault.
  The GetCertificateIssuers operation returns the set of certificate issuer resources in the specified key vault. This operation requires the certificates/manageissuers/getissuers permission.
  
  @param vaultBaseUrl The vault name, for example https://myvault.vault.azure.net.
  @param maxresults Maximum number of results to return in a page. If not specified the service will return up to 25 results.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;CertificateIssuerItem&gt; object