Use the ABCWidgetFactory type parameter defaults where we can to simplify the code.

packages/csvviewer/src/widget.ts

@@ -186,7 +186,7 @@ namespace CSVViewer {
  * A widget factory for CSV widgets.
  */
 export
-class CSVViewerFactory extends ABCWidgetFactory<IDocumentWidget<CSVViewer>, DocumentRegistry.IModel> {
+class CSVViewerFactory extends ABCWidgetFactory<IDocumentWidget<CSVViewer>> {
   /**
    * Create a new widget given a context.
    */

packages/docregistry/src/mimedocument.ts

@@ -224,7 +224,7 @@ class MimeDocument extends DocumentWidget<MimeContent> {
  * An implementation of a widget factory for a rendered mimetype document.
  */
 export
-class MimeDocumentFactory extends ABCWidgetFactory<MimeDocument, DocumentRegistry.IModel> {
+class MimeDocumentFactory extends ABCWidgetFactory<MimeDocument> {
   /**
    * Construct a new markdown widget factory.
    */

packages/imageviewer/src/widget.ts

@@ -199,7 +199,7 @@ class ImageViewer extends Widget {
  * A widget factory for images.
  */
 export
-class ImageViewerFactory extends ABCWidgetFactory<IDocumentWidget<ImageViewer>, DocumentRegistry.IModel> {
+class ImageViewerFactory extends ABCWidgetFactory<IDocumentWidget<ImageViewer>> {
   /**
    * Create a new widget given a context.
    */

tests/test-docmanager/src/manager.spec.ts

@@ -24,7 +24,7 @@ import {
 } from '../../utils';
 
 
-class WidgetFactory extends ABCWidgetFactory<IDocumentWidget, DocumentRegistry.IModel> {
+class WidgetFactory extends ABCWidgetFactory<IDocumentWidget> {
 
   protected createNewWidget(context: DocumentRegistry.Context): IDocumentWidget {
     const content = new Widget();

tests/test-docmanager/src/widgetmanager.spec.ts

@@ -32,7 +32,7 @@ import {
 } from '../../utils';
 
 
-class WidgetFactory extends ABCWidgetFactory<IDocumentWidget, DocumentRegistry.IModel> {
+class WidgetFactory extends ABCWidgetFactory<IDocumentWidget> {
 
   protected createNewWidget(context: DocumentRegistry.Context): IDocumentWidget {
     const content = new Widget();

tests/test-docregistry/src/default.spec.ts

@@ -17,7 +17,7 @@ import {
 } from '../../utils';
 
 
-class WidgetFactory extends ABCWidgetFactory<IDocumentWidget, DocumentRegistry.IModel> {
+class WidgetFactory extends ABCWidgetFactory<IDocumentWidget> {
 
   protected createNewWidget(context: DocumentRegistry.Context): IDocumentWidget {
     const content = new Widget();

tests/test-docregistry/src/registry.spec.ts

@@ -24,7 +24,7 @@ import {
 } from '@jupyterlab/docregistry';
 
 
-class WidgetFactory extends ABCWidgetFactory<IDocumentWidget, DocumentRegistry.IModel> {
+class WidgetFactory extends ABCWidgetFactory<IDocumentWidget> {
 
   protected createNewWidget(context: DocumentRegistry.Context): IDocumentWidget {
     const content = new Widget();