code: public Observable<CertificatePolicy> getCertificatePolicyAsync(String vaultBaseUrl, String certificateName) {
          return getCertificatePolicyWithServiceResponseAsync(vaultBaseUrl, certificateName).map(new Func1<ServiceResponse<CertificatePolicy>, CertificatePolicy>() {
              @Override
              public CertificatePolicy call(ServiceResponse<CertificatePolicy> response) {
                  return response.body();
              }
          });
      }
docs: Lists the policy for a certificate.
  The GetCertificatePolicy operation returns the specified certificate policy resources in the specified key vault. This operation requires the certificates/get permission.
  
  @param vaultBaseUrl The vault name, for example https://myvault.vault.azure.net.
  @param certificateName The name of the certificate in a given key vault.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the CertificatePolicy object