public  void switchToWindow(String windowTitle) {
    Set<String> windows = driver.getWindowHandles();
    for (String window : windows) {
        driver.switchTo().window(window);
        if (driver.getTitle().contains(windowTitle)) {
            return;
        }
    }
}




  public void switchToWindow(int index) {
    Set<String> windows = driver.getWindowHandles();
    int totalWin= windows.size();
    String winTitle = null;
    for(int i=0;i<totalWin;i++) {
        if(i==index) {
        winTitle = windows.toArray()[i].toString();
    }
    }
    driver.switchTo().window(winTitle);
    System.out.println(winTitle);
}