How to access elements inside of a shadow DOM to use with synthetic scripted browser test(New Relic) with Node.js

Question

I am trying to grab and click on a button with New Relic's synthetic scripted browser test utility but the element I'm trying to find is under a #shadow-root in the DOM. Node script looks like:

$browser.get('https://www.null.com').then(() => {
    return $browser.waitForAndFindElement($driver.By.className('btn'), 10000).click();
}):

But it errors out with:

Check failed with task timed out. Error: task timed-out waiting for element to be located using:By(css selector, .btn)

I'm asking to see if there is a work around for grabbing elements in the shadow DOM to be able to use with the selenium webdriver.