interface ServerState {
  readonly ipv4: string;
  locked: boolean;
}

type ServersState = Array<ServerState>
let servers: ServersState = ...

Request failed due to Error: Illegal key values seen in w3c capabilities: [loggingPrefs]

const server = servers.shift();

  if (typeof(server) !== "undefined") {
    servers = [...servers, server];
  }

{
      maxInstances: 1,
      browserName: 'chrome',
      'goog:chromeOptions': {
        args: [
          '--enable-automation',
          '--disable-gpu',
          '--disable-setuid-sandbox',
          '--window-size=1280,900',
          '--disable-xss-auditor',
          '--no-sandbox',
          '--disable-dev-shm-usage'
        ],
        prefs: {
          'intl.accept_languages': 'en,en_UK'
        }
      },
      'goog:loggingPrefs': { driver: 'INFO', browser: 'SEVERE' }
    }

const logs = browser.log('browser').value;

afterTest: function (test) {
        let logEntriesArray = browser.getLogs('browser');
        logEntriesArray.forEach(log => {
            console.log("[" + log.level + "] " + log.timestamp + " : " + log.message);
        })
    },