public function setElement(Element $qtiElement, $body = '', $integrityCheck = true, $requiredPlaceholder = true){
        return $this->setElements(array($qtiElement), $body, $integrityCheck, $requiredPlaceholder);
    }
public function setElement(Element $qtiElement, $body = '', $integrityCheck = true, $requiredPlaceholder = true){
        return $this->setElements(array($qtiElement), $body, $integrityCheck, $requiredPlaceholder);
    }
public function setElement ( Element $ qtiElement , $ body = '' , $ integrityCheck = true , $ requiredPlaceholder = true ) { return $ this -> setElements ( array ( $ qtiElement ) , $ body , $ integrityCheck , $ requiredPlaceholder ) ; }
add one qtiElement into the body
if the body content is not specified, it appends to the end

@access public
@author Sam, <sam@taotesting.com>
@return boolean
add one qtiElement into the body if the body content is not specified it appends to the end