R help - Jan 2007 - Laplace correction for rpart class probability estimate

Hello everybody,
  I'm using rpart to fit a classification tree. I'm interested in the
way rpart estimates the class membership probabilities. Does it
implement the Laplace correction rule? Is there any parameter I can
use to ask rpart to do that?
I was not able to find this option in the manual or on the internet.

thank you,
regards,
Roberto