Keyboard Interactions

driver.get("file://" + __dirname + "/../../site/text_field.html");
driver.findElement(By.id("comments")).sendKeys("Multiple Line\r\n Text");
var elem = driver.findElement(By.id("comments"));
driver.actions()
      .click(elem)
      .keyDown(webdriver.Key.CONTROL)
      .sendKeys("a")
      .keyUp(webdriver.Key.CONTROL)
      .perform();
// this different from click element, the key is send to browser directly
driver.actions()
      .sendKeys(webdriver.Key.BACK_SPACE)
      .perform();