Is there any ways to get style for pseudo-class?

• jest-glamor-react version: v4.2.1
• node version: v8.9.4
• npm (or yarn) version: v5.6.0

Relevant code or config

const TestComp = glamorous.div({
  '::after': {
    backgroundColor: 'white',
  },
});

it('should have white background', () => {
  const component = enzyme.shallow(<TestComp />);
  expect(component).toHaveStyleRule(/* What should I do ??? */);
});

What you did: Try to test pseudo-class style

What happened: No way to test it

Problem description:

Suggested solution: Add some matchers? or add functions to the matcher?