Should fixture.destroy() be explicit in Angular 2+ unit testing

For unit testing with Karma/Jasmine in Angular 2+, should the fixture destruction be explicit?

afterEach(() => fixture.destroy());

and what are the consequences if not destroying the fixture (i.e. is it called behind the scenes by the framework or does the fixture persist leading to side-effects)?

Angular docs on the topic don't suggest the right answer. What are your thoughts ? Thanks