async function performChecks(autocomplete, index, valueOnClose) {
        await el.updateComplete;
        el.opened = true;
        el.setCheckedIndex(-1);
        await el.updateComplete;
        el.autocomplete = autocomplete;
        el.setCheckedIndex(index);
        await el.updateComplete;
        el.opened = false;
        await el.updateComplete;
        expect(_inputNode.value).to.equal(valueOnClose, autocomplete);
      }
@param {'none' | 'list' | 'inline' | 'both'} autocomplete
@param {number|number[]} index
@param {string} valueOnClose