message: useRealTimers in  onCssReady test case
diff: @@ -25,14 +25,20 @@ import { onCssReady } from '../transformers';
  const docStorageUrl: string =
  'https://techdocs-mock-sites.storage.googleapis.com';
  -jest.useFakeTimers();
  -
  const fixture = `
  <link rel="stylesheet" href="${docStorageUrl}/test.css" />
  <link rel="stylesheet" href="http://example.com/test.css" />
  `;
  describe('onCssReady', () => {
  + beforeAll(() => {
  + jest.useFakeTimers();
  + });
  +
  + afterAll(() => {
  + jest.useRealTimers();
  + });
  +
  beforeEach(() => {
  mockStylesheetEventListener(100);
  });
  