[JAVA3D] HELP

[hl]

Hello,I don't know how to program my interactive apps by using class PickMouseBehavior. Can you give me example codes?or tell me where to find answer.    I read the following words from Java3D API specification :"Class PickMouseBehavior is base class that allows users to adding picking and mouse manipulation to the scene graph (see PickDragBehavior for an example of how to extend this base class). This class is useful for interactive apps. ", but I can not find example PickDragBehavior, can you help me?    Thanks .                                        HuangLing