code: public Observable<Page<SecretItem>> getSecretVersionsAsync(final String vaultBaseUrl, final String secretName) {
          return getSecretVersionsWithServiceResponseAsync(vaultBaseUrl, secretName)
              .map(new Func1<ServiceResponse<Page<SecretItem>>, Page<SecretItem>>() {
                  @Override
                  public Page<SecretItem> call(ServiceResponse<Page<SecretItem>> response) {
                      return response.body();
                  }
              });
      }
docs: List all versions of the specified secret.
  The full secret identifier and attributes are provided in the response. No values are returned for the secrets. This operations requires the secrets/list permission.
  
  @param vaultBaseUrl The vault name, for example https://myvault.vault.azure.net.
  @param secretName The name of the secret.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;SecretItem&gt; object