How to use the @jupyterlab/testutils.NBTestUtils.createNotebookFactory function in @jupyterlab/testutils

RawCellModel,
  RawCell,
  Cell
} from '@jupyterlab/cells';

import { INotebookModel, NotebookModel } from '@jupyterlab/notebook';

import { Notebook, StaticNotebook } from '@jupyterlab/notebook';

import {
  NBTestUtils,
  framePromise,
  signalToPromise
} from '@jupyterlab/testutils';

const contentFactory = NBTestUtils.createNotebookFactory();
const editorConfig = NBTestUtils.defaultEditorConfig;
const rendermime = NBTestUtils.defaultRenderMime();

const options: Notebook.IOptions = {
  rendermime,
  contentFactory,
  mimeTypeService: NBTestUtils.mimeTypeService,
  editorConfig
};

function createWidget(): LogStaticNotebook {
  const model = new NotebookModel();
  const widget = new LogStaticNotebook(options);
  widget.model = model;
  return widget;
}

beforeEach(() => {
      widget = new Notebook({
        rendermime,
        contentFactory: NBTestUtils.createNotebookFactory(),
        mimeTypeService: NBTestUtils.mimeTypeService
      });
      const model = new NotebookModel();
      model.fromJSON(NBTestUtils.DEFAULT_CONTENT);
      widget.model = model;

      widget.activeCellIndex = 0;
    });

RawCellModel,
  RawCell,
  Cell
} from '@jupyterlab/cells';

import { INotebookModel, NotebookModel } from '@jupyterlab/notebook';

import { Notebook, StaticNotebook } from '@jupyterlab/notebook';

import {
  NBTestUtils,
  framePromise,
  signalToPromise
} from '@jupyterlab/testutils';

const contentFactory = NBTestUtils.createNotebookFactory();
const editorConfig = NBTestUtils.defaultEditorConfig;
const rendermime = NBTestUtils.defaultRenderMime();

const options: Notebook.IOptions = {
  rendermime,
  contentFactory,
  mimeTypeService: NBTestUtils.mimeTypeService,
  editorConfig
};

function createWidget(): LogStaticNotebook {
  const model = new NotebookModel();
  const widget = new LogStaticNotebook(options);
  widget.model = model;
  return widget;
}

beforeEach(() => {
      widget = new Notebook({
        rendermime,
        contentFactory: NBTestUtils.createNotebookFactory(),
        mimeTypeService: NBTestUtils.mimeTypeService
      });
      const model = new NotebookModel();
      model.fromJSON(NBTestUtils.DEFAULT_CONTENT);
      widget.model = model;

      widget.activeCellIndex = 0;
    });