code: public Observable<Page<StorageAccountCredentialInner>> listByDataBoxEdgeDeviceNextAsync(final String nextPageLink) {
          return listByDataBoxEdgeDeviceNextWithServiceResponseAsync(nextPageLink)
              .map(new Func1<ServiceResponse<Page<StorageAccountCredentialInner>>, Page<StorageAccountCredentialInner>>() {
                  @Override
                  public Page<StorageAccountCredentialInner> call(ServiceResponse<Page<StorageAccountCredentialInner>> response) {
                      return response.body();
                  }
              });
      }
docs: Gets all the storage account credentials in a data box edge/gateway device.
  
  @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;StorageAccountCredentialInner&gt; object