It is a Jest-ism that shouldn't be in our open source package.
People using Jest can implement a similar pattern directly.
componentDidMount() {
        this.setState({}, (...args) => (mockArgs = args));
      }
      render() {
        return false;
      }
    }
    ReactTestUtils.renderIntoDocument(<Component />);
    expect(mockArgs.length).toEqual(0);
  });
});