code: public Observable<Page<DeletedSecretItem>> getDeletedSecretsNextAsync(final String nextPageLink) {
          return getDeletedSecretsNextWithServiceResponseAsync(nextPageLink)
              .map(new Func1<ServiceResponse<Page<DeletedSecretItem>>, Page<DeletedSecretItem>>() {
                  @Override
                  public Page<DeletedSecretItem> call(ServiceResponse<Page<DeletedSecretItem>> response) {
                      return response.body();
                  }
              });
      }
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 nextPageLink The NextLink from the previous successful call to List operation.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;DeletedSecretItem&gt; object