public function testGroups()
 {
     $groupsObject = new GroupsObject();
     $this->assertEquals($this->getContent('groups_all'), $this->serializer->serialize($groupsObject, $this->getFormat()));
     $this->serializer->setGroups(array("foo"));
     $this->assertEquals($this->getContent('groups_foo'), $this->serializer->serialize($groupsObject, $this->getFormat()));
     $this->serializer->setGroups(array("foo", "bar"));
     $this->assertEquals($this->getContent('groups_foobar'), $this->serializer->serialize($groupsObject, $this->getFormat()));
     $this->serializer->setGroups(null);
     $this->assertEquals($this->getContent('groups_all'), $this->serializer->serialize($groupsObject, $this->getFormat()));
     $this->serializer->setGroups(array());
     $this->assertEquals($this->getContent('groups_all'), $this->serializer->serialize($groupsObject, $this->getFormat()));
     $this->serializer->setGroups(array('Default'));
     $this->assertEquals($this->getContent('groups_default'), $this->serializer->serialize($groupsObject, $this->getFormat()));
 }