code: @Override
    public void stopSession() {
      serverInstrumentation.finishAllActivities();
      this.activeWindowType = WindowType.NATIVE_APP.name();
      this.session = null;
      nativeSearchScope = null;
      selendroidNativeDriver = null;
      selendroidWebDriver = null;
      webviewSearchScope = null;
    }
docs: /*
  (non-Javadoc)
  
  @see org.openqa.selenium.android.server.AndroidDriver#stopSession()