code: public Observable<ServiceResponse<Page<DeletedKeyItem>>> getDeletedKeysSinglePageAsync(final String vaultBaseUrl) {
          if (vaultBaseUrl == null) {
              throw new IllegalArgumentException("Parameter vaultBaseUrl is required and cannot be null.");
          }
          if (this.apiVersion() == null) {
              throw new IllegalArgumentException("Parameter this.apiVersion() is required and cannot be null.");
          }
          final Integer maxresults = null;
          String parameterizedHost = Joiner.on(", ").join("{vaultBaseUrl}", vaultBaseUrl);
          return service.getDeletedKeys(maxresults, this.apiVersion(), this.acceptLanguage(), parameterizedHost, this.userAgent())
              .flatMap(new Func1<Response<ResponseBody>, Observable<ServiceResponse<Page<DeletedKeyItem>>>>() {
                  @Override
                  public Observable<ServiceResponse<Page<DeletedKeyItem>>> call(Response<ResponseBody> response) {
                      try {
                          ServiceResponse<PageImpl<DeletedKeyItem>> result = getDeletedKeysDelegate(response);
                          return Observable.just(new ServiceResponse<Page<DeletedKeyItem>>(result.body(), result.response()));
                      } catch (Throwable t) {
                          return Observable.error(t);
                      }
                  }
              });
      }
docs: Lists the deleted keys in the specified vault.
  Retrieves a list of the keys in the Key Vault as JSON Web Key structures that contain the public part of a deleted key. This operation includes deletion-specific information. The Get Deleted Keys operation is applicable for vaults enabled for soft-delete. While the operation can be invoked on any vault, it will return an error if invoked on a non soft-delete enabled vault. This operation requires the keys/list permission.
  
  @param vaultBaseUrl The vault name, for example https://myvault.vault.azure.net.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the PagedList&lt;DeletedKeyItem&gt; object wrapped in {@link ServiceResponse} if successful.