def get_pr_reviews(pr):
    """Gets a list of all submitted reviews on a PR. Does not list requested
    reviews."""
    # Required to access the PR review API.
    headers = {'Accept': 'application/vnd.github.black-cat-preview+json'}
    reviews = pr.session.get(
        'https://api.github.com/repos/{}/{}/pulls/{}/reviews'.format(
            pr.repository[0], pr.repository[1], pr.number),
        headers=headers).json()

    return reviews