public function testGetExtendedMergeVars()
{
$this->assertEmpty($this->entity->getExtendedMergeVars());
$var = new ExtendedMergeVar();
$this->entity->addExtendedMergeVar($var);
$extendedMergeVars = $this->entity->getExtendedMergeVars();
$this->assertNotEmpty($extendedMergeVars);
$this->assertContains($var, $extendedMergeVars);
$this->entity->removeExtendedMergeVar($var);
$this->assertEmpty($this->entity->getExtendedMergeVars());
}