code: public Observable<SecretBundle> getSecretAsync(String vaultBaseUrl, String secretName, String secretVersion) {
          return getSecretWithServiceResponseAsync(vaultBaseUrl, secretName, secretVersion).map(new Func1<ServiceResponse<SecretBundle>, SecretBundle>() {
              @Override
              public SecretBundle call(ServiceResponse<SecretBundle> response) {
                  return response.body();
              }
          });
      }
docs: Get a specified secret from a given key vault.
  The GET operation is applicable to any secret stored in Azure Key Vault. This operation requires the secrets/get permission.
  
  @param vaultBaseUrl The vault name, for example https://myvault.vault.azure.net.
  @param secretName The name of the secret.
  @param secretVersion The version of the secret.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the SecretBundle object