Sokil\Mongo\CollectionLockTest::testOptimisticLock PHP Method

    public function testOptimisticLock()
    {
        // init connection
        $client = new Client(getenv('PHPMONGO_DSN') ? getenv('PHPMONGO_DSN') : null);
        $client->map(array('test' => array('phpmongo_test_collection' => array('lock' => Definition::LOCK_OPTIMISTIC))));
        // get collection
        $collection = $client->getDatabase('test')->getCollection('phpmongo_test_collection');
        // create document
        $document = $collection->createDocument(array('param' => 'value'))->save();
        // check version field set
        $this->assertEquals(null, $document->get('__version__'));
        // first read of document
        $doc1 = $collection->getDocumentDirectly($document->getId());
        // second read of document
        $doc2 = $collection->getDocumentDirectly($document->getId());
        // update first document
        $doc1->set('param', 'valueOfDoc1')->save();
        $this->assertEquals(1, $doc1->get('__version__'));
        $this->assertEquals(null, $doc2->get('__version__'));
        // try to update second document
        $doc2->set('param', 'valueOfDoc2')->save();
    }