how to predict with logistic model in package logistf ?

dear community,
     I am a beginer in R , and can't predict with logistic model  in package 
logistf,
could anyone help me ? thanks !

the following is my command and result :

library(logistf)
data(sex2)
fit<-logistf(case ~ age+oc+vic+vicl+vis+dia, data=sex2)
predict(fit,newdata=sex2)

Error in predict(fit, newdata = sex2) : no applicable method for 
"predict"