It is a Jest-ism that shouldn't be in our open source package.
People using Jest can implement a similar pattern directly.
render() {
        return null;
      }
    }
    class Wrapper extends React.Component {
      render() {
        return (
          <div>
            <Child />
          </div>
        );
      }
    }
    const renderedComponent = ReactTestUtils.renderIntoDocument(<Wrapper />);
    const scryResults = ReactTestUtils.scryRenderedComponentsWithType(
      renderedComponent,
      Child,
    );
    expect(scryResults.length).toBe(1);
  });
  it('can scryRenderedDOMComponentsWithClass with TextComponent', () => {
    class Wrapper extends React.Component {