import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;
import org.testng.Assert;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;

public class UITestSample {

    private WebDriver driver;

    @BeforeMethod
    public void setup() {
        System.setProperty("webdriver.chrome.driver", "path/to/chromedriver");
        driver = new ChromeDriver();
        driver.get("http://example.com/login");
    }

    @Test
    public void testSuccessfulLogin() {
        WebElement usernameField = driver.findElement(By.id("username"));
        WebElement passwordField = driver.findElement(By.id("password"));
        WebElement loginButton = driver.findElement(By.id("loginButton"));

        usernameField.sendKeys("testUser");
        passwordField.sendKeys("testPassword");
        loginButton.click();

        WebElement successMessage = driver.findElement(By.id("success"));
        Assert.assertTrue(successMessage.isDisplayed());
    }
}