public function testAddClass()
{
$element = new Element('test');
$element->setClass('yo');
$this->assertEquals('yo', $element->getClass());
$element->addClass('yo');
$this->assertEquals('yo', $element->getClass());
$element->addClass('yo2');
$this->assertEquals('yo yo2', $element->getClass());
$element->removeClass('yo');
$this->assertEquals('yo2', $element->getClass());
}