[Pharo-users] Can't able to understand the code

I try to run the code which attached below. But i dont have idea what i need to write on playground to run the code. can anyone explain what happen actually using this class>>primImage: aFormat width: aWidth height:aHeight <http://forum.world.st/file/t372453/prob.png> -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html