Writing React TestUtils test case for function without parameters

So I have a function to remove all tabbing from a particular page. There is a variable declared in this function that does the work. I need to pass dummy value to this variable so that the value will pass and function executes.

How do I write test case using ReactJS TestUtils for the following.

_removeAllTabbing() {
const accordionTitleAnchors = [
    document.getElementById('accordion-panel-1').firstChild,
    document.getElementById('accordion-panel-2').firstChild,
    document.getElementById('accordion-panel-3').firstChild,
    document.getElementById('accordion-panel-4').firstChild,
    document.getElementById('accordion-panel-5').firstChild
];

_.each(accordionTitleAnchors, accordionTitleAnchor => {
    this._removeTabbing(accordionTitleAnchor);
});

}

So far I have this

xit('should call _removeAllTabbing function', () => {
    const educate = new EducateAccordion();
    const accordionTitleAnchors = TestUtils.scryRenderedDOMComponentsWithClass(this.component, 'panel-title');;

    educate._removeAllTabbing(accordionTitleAnchors);
});

Also, it will be great if anyone can share some docs/articles for testing different front end scenarios.

So renderIntoDocument didn't work. :( wonder why?

Here is the code that works for me.

it('should validate _removeAllTabbing function', () => {
        const educate = new EducateAccordion();
        const activeKey = 1;

        const dummyElement = document.createElement('div');

        for (let i = 1; i <= 5; i++) {
            const temp = document.createElement('div');

            temp.setAttribute('id', 'accordion-panel-' + i);

            const temp2 = document.createElement('div');

            temp2.setAttribute('class', 'panel-title');
            temp2.setAttribute('role', 'tablist');

            temp.appendChild(temp2);
            dummyElement.appendChild(temp);
        }

        document.body.appendChild(dummyElement);

        educate._removeAllTabbing();

        this.accordionDummy = ReactDOM.findDOMNode(dummyElement);

        this.accordionTitleAnchors = this.accordionDummy.getElementsByClassName('panel-title');

        _.each(this.accordionTitleAnchors, (item) => {
            expect(item.getAttribute('tabIndex')).to.equal('-1');
        });
    });

Need to figure out ways to test navigation portion of the application front-end