code: public ServiceFuture<List<DeletedSecretItem>> getDeletedSecretsAsync(final String vaultBaseUrl, final ListOperationCallback<DeletedSecretItem> serviceCallback) {
          return AzureServiceFuture.fromPageResponse(
              getDeletedSecretsSinglePageAsync(vaultBaseUrl),
              new Func1<String, Observable<ServiceResponse<Page<DeletedSecretItem>>>>() {
                  @Override
                  public Observable<ServiceResponse<Page<DeletedSecretItem>>> call(String nextPageLink) {
                      return getDeletedSecretsNextSinglePageAsync(nextPageLink);
                  }
              },
              serviceCallback);
      }
docs: Lists deleted secrets for the specified vault.
  The Get Deleted Secrets operation returns the secrets that have been deleted for a vault enabled for soft-delete. This operation requires the secrets/list permission.
  
  @param vaultBaseUrl The vault name, for example https://myvault.vault.azure.net.
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object