How to setBins only for the fft convolution

In the RooFit users manual, it says to do this to set the number of bins for a RooRealVar only for the FFT convolution:

// Define sampling frequency
t.setBins(“fft”,10000) ;

(see page 40 of … .91-33.pdf)

This, however, did not work, even when I reversed the order of the arguments to setBins.

Did something change since the manual was written?