public function testSerialize() {
$this->metadata
->addConstraint(new ConstraintA(array(
'property1' => 'A',
)));
$this->metadata
->addConstraint(new ConstraintB(array(
'groups' => 'TestGroup',
)));
$metadata = unserialize(serialize($this->metadata));
$this
->assertEquals($this->metadata, $metadata);
}