[R-SIG-Finance] How to add new data to be predicted with fGarch?

[Be Water]

## R version 3.3.1 (2016-06-21)
## Platform: x86_64-w64-mingw32/x64 (64-bit)
## Running under: Windows>= 8 x64 (build 9200)

library(fGarch)

## Data simulation
set.seed(345)
ar.sim <- arima.sim(model=list(ar=c(.9,-.2)), n=1000) 
tail(ar.sim) 
plot(ar.sim)

## Model fit 
model = garchFit( ~ arma(1, 2) + garch(1, 1), Data=ar.sim) 
print(model)

##QUESTION: How to add new data to be predicted?
help('predict-methods', pac=fGarch) ## I cannot find any example

newdata <- data.frame(x= -0.3)
newdata <- -0.3
predict(model, newdata = newdata, n.ahead=1)

Thanks