代码：
Size visibleSize = Director::getInstance()->getVisibleSize();
auto border = Sprite::create(“border.png”);
Size borderSize = border->getContentSize();
auto body = PhysicsBody::createBox(borderSize);
body->setDynamic(false);
body->setCategoryBitmask(1); // 0001
body->setCollisionBitmask(1); // 0001
body->setContactTestBitmask(1); // 0001
border->setPhysicsBody(body);
border->setPosition(Point(visibleSize.width * 0.5f, visibleSize.height * 0.15f));
border->setRotation(90.0f);
this->addChild(border);
这个border->setRotation(90.0f);没有效果这是怎么回事，
node的源码：
if (_physicsBody && _physicsBody->getWorld()) {
_physicsBody->getWorld()->_updateBodyTransform = true;
}
_physicsBody->getWorld()这个是null
我上面的语句有什么问题吗？