How to close the second tab once it’s functionality is done , in Webdriver Java.

The code is

public static void closeSecondTabAndSwitchToFirstTab(WebDriver driver){
        ArrayList<String> tab = new ArrayList<String> (driver.getWindowHandles());
        System.out.println("No of tabs are  --"+tab);
        if (tab.size() == 1) {
            System.out.println("No additional tabs.");
            driver.switchTo().window(tab.get(0));
        } else {
            //Close the second window.
            driver.switchTo().window(tab.get(1));
            driver.close();
            System.out.println("Closed the second tab using index 1.");
            driver.switchTo().window(tab.get(0));
            System.out.println("Switched to main window using index 0.");
        }
    }