switch窗口句柄

        Set<String>  windows = browser.getWebDriver().getWindowHandles();  //获得所有窗口句柄
        for (String string : windows) {
            System.out.println(string);                                    //打印所有窗口句柄
        }
        String currWin = browser.getWebDriver().getWindowHandle();
        System.out.println(currWin);
        Iterator<String> it = windows.iterator();
        while(it.hasNext()) {
            String handle = it.next();
            if(currWin.equals(handle))
                continue;
            browser.getWebDriver().switchTo().window(handle);               //切换窗口
        }
        

        browser.pause(5);

        String Win2 = browser.getWebDriver().getWindowHandle(); 
        System.out.println(Win2);                                           //再次打印当前窗口句柄,与currWin不一样