src/vs/workbench/contrib/notebook/browser/view/cellParts/cellOutput.ts/CellOutputElement/_renderMissingRenderer
class CellOutputElement:	private _renderMissingRenderer(viewModel: ICellOutputViewModel, preferredMimeType: string | undefined): IInsetRenderOutput {
		if (!viewModel.model.outputs.length) {
			return this._renderMessage(viewModel, nls.localize('empty', "Cell has no output"));
		}

		if (!preferredMimeType) {
			const mimeTypes = viewModel.model.outputs.map(op => op.mime);
			const mimeTypesMessage = mimeTypes.join(', ');
			return this._renderMessage(viewModel, nls.localize('noRenderer.2', "No renderer could be found for output. It has the following mimetypes: {0}", mimeTypesMessage));
		}

		return this._renderSearchForMimetype(viewModel, preferredMimeType);
	}