[Pharo-project] Q: is there a way to get the classes referenced by a class?

Hi, I'm trying to get a "dependency map" of a certain project (playing with pavel's kernel image, I'm trying to figure out how to feed it with all needed dependences). What I'm doing now is very inneficient (usign #allCallsOn and reversing the search), and I'm sure there should be something better... Thanks, Esteban