driver.manage().window().maximize();
driver.manage().deleteAllCookies();
under the browser.
example:
@BeforeClass
public void setup()
{
WebDriverManager.chromedriver().setup();
//System.setProperty("webdriver.chrome.driver","D:\\Eclipse\\eSchoolJourneyQA\\Driver\\chromedriver.exe"); // 58 min
driver=new ChromeDriver();
driver.manage().window().maximize();
driver.manage().deleteAllCookies();
}