public function testToAndFromString()
{
$this->custom->setText('value');
$this->assertTrue($this->custom->getText() == 'value');
$this->custom->setColumnName('column_name');
$this->assertTrue($this->custom->getColumnName() == 'column_name');
$newCustom = new Extension\Custom();
$doc = new \DOMDocument();
$doc->loadXML($this->custom->saveXML());
$newCustom->transferFromDom($doc->documentElement);
$this->assertTrue($this->custom->getText() == $newCustom->getText());
$this->assertTrue($this->custom->getColumnName() == $newCustom->getColumnName());
}