src/vs/workbench/contrib/notebook/browser/notebookEditorWidget.ts/NotebookEditorWidget/createMarkupPreview
class NotebookEditorWidget:	async createMarkupPreview(cell: MarkupCellViewModel) {
		if (!this._webview) {
			return;
		}

		if (!this._webview.isResolved()) {
			await this._resolveWebview();
		}

		if (!this._webview || !this._list.webviewElement) {
			return;
		}

		if (!this.viewModel) {
			return;
		}

		if (this.viewModel.getCellIndex(cell) === -1) {
			return;
		}

		if (this.cellIsHidden(cell)) {
			return;
		}

		const webviewTop = parseInt(this._list.webviewElement.domNode.style.top, 10);
		const top = !!webviewTop ? (0 - webviewTop) : 0;

		const cellTop = this._list.getAbsoluteTopOfElement(cell);
		await this._webview.showMarkupPreview({
			mime: cell.mime,
			cellHandle: cell.handle,
			cellId: cell.id,
			content: cell.getText(),
			offset: cellTop + top,
			visible: true,
			metadata: cell.metadata,
		});
	}