Set cookie on lighthouse - ugly hack

driver.js

    // Set request blocking before any network activity
    // No "clearing" is done at the end of the pass since blockUrlPatterns([]) will unset all if
    // neccessary at the beginning of the next pass.
    await passContext.driver.blockUrlPatterns(blockedUrls);
    await passContext.driver.setExtraHTTPHeaders(passContext.settings.extraHeaders);
    // Add this call for setting the cookie.
    await passContext.driver.setCookie();

gather-runner.js

class Driver {

  /**
   * Needs this method added to the Driver class.
   */
  async setCookie() {
    let val = {
      name: 'cookie_name',
      value: 'cookie_value',
      domain: 'example.local',
      path: '/'
    };
    return this.sendCommand('Network.setCookie', value);
  }

}