How to use org.openqa.selenium

 private static Function<WebDriver,WebElement> presenceOfElementLocated(final By locator) {
  return new Function<WebDriver, WebElement>() {
    @Override
    public WebElement apply(WebDriver driver) {
      return driver.findElement(locator);
    }
  };
}

 WebElement element = driver.findElement(By.id("foo"));
// DOM changes - page is refreshed, or element is removed and re-added
element.click();

 // Assume driver is a valid WebDriver instance that
// has been properly instantiated elsewhere.
WebElement element = driver.findElement(By.id("gbqfd"));
JavascriptExecutor executor = (JavascriptExecutor)driver;
executor.executeScript("arguments[0].click();", element);

  private void signIn(String userName, String password) {
    webDriver.findElement(By.name("username")).sendKeys(userName);
    webDriver.findElement(By.name("password")).sendKeys(password);
    webDriver.findElement(By.xpath("//input[@value='Sign in']")).click();
  }
}

private void performLogin(String username) {
  webDriver.get(zoneUrl + "/logout.do");
  webDriver.manage().deleteAllCookies();
  webDriver.get(zoneUrl + "/login");
  webDriver.findElement(By.name("username")).sendKeys(username);
  webDriver.findElement(By.name("password")).sendKeys(USER_PASSWORD);
  webDriver.findElement(By.xpath("//input[@value='Sign in']")).click();
}

  private void loginThroughDiscovery(String userEmail, String password) {
    webDriver.findElement(By.id("email")).sendKeys(userEmail);
    webDriver.findElement(By.cssSelector(".form-group input[value='Next']")).click();
    webDriver.findElement(By.id("password")).sendKeys(password);
    webDriver.findElement(By.xpath("//input[@value='Sign in']")).click();
  }
}

@Override
public Dimension getScreenSize() {
  org.openqa.selenium.Dimension windowSize = driver.manage().window().getSize();
  return new Dimension(windowSize.getWidth(), windowSize.getHeight());
}

/**
 * Changes the size of current browser for current test thread
 *
 * @param width  The width of browser window
 * @param height The height of browser window
 */
public void resize(int width, int height) {
  getDriver().manage().window().setSize(new Dimension(width, height));
}

@Override
public WebDriver apply(WebDriver driver) {
 try {
  return driver.switchTo().frame(driver.findElement(locator));
 } catch (NoSuchFrameException e) {
  return null;
 } catch (WebDriverException e) {
  return null;
 }
}

  private void doLogout() {
    webDriver.get(baseUrl + "/logout.do");
    webDriver.manage().deleteAllCookies();
  }
}

public LoginForm password(String password) {
  this.password.sendKeys(password);
  return this;
}

public WebElement findClientRegistrationByName(String clientName) {
  return DefaultLoginPage.this.driver.findElement(By.linkText(clientName));
}

private static String getText(WebElement element) {
 try {
  return element.getText();
 } catch (WebDriverException elementDisappeared) {
  return elementDisappeared.toString();
 }
}

@Override
public void refresh() {
  driver.navigate().refresh();
}

public void attemptLogin(String username, String password) {
  webDriver.findElement(By.name("username")).sendKeys(username);
  webDriver.findElement(By.name("password")).sendKeys(password);
  webDriver.findElement(By.xpath("//input[@value='Sign in']")).click();
}

public LoginForm username(String username) {
  this.username.sendKeys(username);
  return this;
}

 WebDriver driver = new AnyDriverYouWant();
JavascriptExecutor js;
if (driver instanceof JavascriptExecutor) {
  js = (JavascriptExecutor)driver;
} // else throw...

// later on...
js.executeScript("return document.getElementById('someId');");

private void changePassword(String originalPassword, String newPassword, String confirmPassword) {
  webDriver.findElement(By.xpath("//*[text()='"+userEmail+"']")).click();
  webDriver.findElement(By.linkText("Account Settings")).click();
  webDriver.findElement(By.linkText("Change Password")).click();
  webDriver.findElement(By.name("current_password")).sendKeys(originalPassword);
  webDriver.findElement(By.name("new_password")).sendKeys(newPassword);
  webDriver.findElement(By.name("confirm_password")).sendKeys(confirmPassword);
  webDriver.findElement(By.xpath("//input[@value='Change password']")).click();
}

public LoginForm username(String username) {
  this.username.sendKeys(username);
  return this;
}

public LoginForm password(String password) {
  this.password.sendKeys(password);
  return this;
}