[SOLVED] About PhysicsCollisionHandler. AssertionError: targ

My code:

self.smiley = loader.loadModel('smiley')
self.ball = self.smiley.attachNewNode(CollisionNode('sphere'))
self.ball.node().addSolid(CollisionSphere(0,0,0,1))
self.ball.setPos(-3,0,0)
self.ball.show()
self.ball.reparentTo(render)
self.smiley.reparentTo(self.ball)

self.pusher = PhysicsCollisionHandler()
self.pusher.addCollider(self.ball, self.smiley)

Then, I get:

  File "main.py", line 38, in __init__
    self.pusher.addCollider(self.ball, self.smiley)
AssertionError: target.node()->is_of_type(ActorNode::get_class_type()) at line 212 of panda/src/physics/physicsCollisionHandler.cxx

I try use tube insert sphere, but still.

The error message says that you need to pass it an ActorNode.

Thank you.