docs: function(opt_config, opt_service, opt_flow) {
    var service = opt_service || getDefaultService();
    var executor = executors.createExecutor(service.start());
  
    var capabilities =
        opt_config instanceof Options ? opt_config.toCapabilities() :
        (opt_config || webdriver.Capabilities.chrome());
  
    var driver = webdriver.WebDriver.createSession(
        executor, capabilities, opt_flow);
  
    webdriver.WebDriver.call(
        this, driver.getSession(), executor, driver.controlFlow());
  }