How to sendtext in ckeditor through htmlunitdriver in webdriver

Question

How to send text in ckeditor through htmlunitdriver in web driver? Below code is working for firefoxdriver but not for htmlunitdriver .

driver.switchTo().frame(driver.findElement(By.xpath("//iframe[@id='scayt_0']")));

WebElement elem = driver.findElement(By.tagName("body"));

 elem.click();

 elem.sendKeys("djkds");

driver.switchTo().defaultContent();

Any suggestion?