Attach (recommended) or Link to PDF file here:

Configuration:
- Web browser and its version:
Firefox/Chrome, latest version
- Operating system and its version:
Linux,Windows,mac
- PDF.js version:
v2.12.313
- Is a browser extension:
no

Steps to reproduce the problem:
1. create a custom viewer with 
```
async function getViewer() {
const viewer = await import(/* webpackChunkName: 'pdfviewer' */ 'pdfjs-dist/web/pdf_viewer');
const eventBus = new viewer.EventBus();
return viewer.PDFSinglePageViewer({
        container,
        eventBus,
        useOnlyCssZoom: USE_ONLY_CSS_ZOOM,
        // We can enable text/annotations layers, if needed
        textLayerFactory: new viewer.DefaultTextLayerFactory(),
        annotationLayerFactory: new viewer.DefaultAnnotationLayerFactory(),
        // textLayerMode: TextLayerMode.ENABLE,
        // currently the SVG renderer is not supported
        // and it has problems with telekom documents
        // so it will be disabled until it is feature complete
        // renderer: 'svg'
    });
}
```
2. console prints an error:
```
Unable to get page for page view TypeError: this.linkService._cachedPageNumber is not a function
    ensurePdfPageLoaded_fn base_viewer.js:1502
```
    
Looks like the problem is `IPDFLinkService` which is actually using the default one `this.linkService = options.linkService || new SimpleLinkService();` which does not have this function. of course we can use `PDFLinkService` which will probably work.

}
              }
            );
            if (pageNum % PagesCountLimit.PAUSE_EAGER_PAGE_INIT === 0) {
              await promise;
            }
          }
        });
        this.eventBus.dispatch("pagesinit", { source: this });
        pdfDocument.getMetadata().then(({ info }) => {
          if (pdfDocument !== this.pdfDocument) {
            return; 
          }
          if (info.Language) {
            this.viewer.lang = info.Language;
          }
        });
        if (this.defaultRenderingQueue) {
          this.update();
        }
      })
      .catch(reason => {
        console.error("Unable to initialize viewer", reason);
        this._pagesCapability.reject(reason);
      });
  }
  /**
   * @param {Array|null} labels
   */
  setPageLabels(labels) {