Water and Buoyancy with Chipmunk

cocos2d-x JavaScript
1

Hi, I’m trying to make the same effect in this page:
http://cocos2d-x.org/js-tests/
pls select Chipmunk and select Buoyancy
if you loo in the code at the bottom of this page you can see as strange code :

e81176d3dde961d5.png794×369

how to use this code ?

Thank you.