public function testSave()
{
$this->object->save((object) array('x' => 1));
$a = $this->object->findOne();
$id1 = $a['_id'];
$a['x'] = 2;
$this->object->save($a);
$id2 = $a['_id'];
$this->assertEquals($id1, $id2);
$a['y'] = 3;
$this->object->save($a);
$this->assertEquals($this->object->count(), 1);
$a = $this->object->findOne();
$this->assertEquals($a['x'], 2);
}
