I have create testcases in eclipse.but while runnig testng.xml file it's open in new browser every time.how to run it in single browser.i am calling below for every testcases so it's open in new browser.

    @BeforeClass
    	public static void setup()
    	{
    		
    		
    		System.setProperty("webdriver.chrome.driver", "E:\\Selenium Jar\\chromedriver.exe");
    		ChromeOptions options = new ChromeOptions();
    		options.addArguments("--disable-extensions");
    		driver = new ChromeDriver(options);
    		driver.manage().window().maximize();
    		
    	}