src/vs/workbench/contrib/notebook/browser/diff/notebookTextDiffEditor.ts/NotebookTextDiffEditor/_createOriginalWebview
class NotebookTextDiffEditor:	private async _createOriginalWebview(id: string, resource: URI): Promise<void> {
		if (this._originalWebview) {
			this._originalWebview.dispose();
		}

		this._originalWebview = this.instantiationService.createInstance(BackLayerWebView, this, id, resource, this._notebookOptions.computeDiffWebviewOptions(), undefined) as BackLayerWebView<IDiffCellInfo>;
		// attach the webview container to the DOM tree first
		this._list.rowsContainer.insertAdjacentElement('afterbegin', this._originalWebview.element);
		await this._originalWebview.createWebview();
		this._originalWebview.element.style.width = `calc(50% - 16px)`;
		this._originalWebview.element.style.left = `16px`;
	}