driver.findElement(By.cssSelector("body")).sendKeys(Keys.CONTROL +"a");

driver.findElement(By.tagName("body")).sendKeys(Keys.chord(Keys.CONTROL,"a"));

driver.findElement(By.cssSelector("body")).sendKeys(Keys.CONTROL +"t");

driver.findElement(By.tagName("body")).sendKeys(Keys.chord(Keys.CONTROL,"n"));

try {
    Robot robot = new Robot();
    robot.keyPress(KeyEvent.VK_CONTROL);
    robot.keyPress(KeyEvent.VK_T);
    robot.keyRelease(KeyEvent.VK_CONTROL);
    robot.keyRelease(KeyEvent.VK_T);
} catch (AWTException e) {
    e.printStackTrace();
}