How to do equivalent of an irfft?

Hi, thanks for your work on this package. I was wondering if it's possible, how I could do an `irfft`. For example, currently for an equidistantly spaced signal I do the following:

```julia
using FFTW
irfft(data, 2length(data)-1)
```

What would be the closest analogue with NFFT.jl? `data` will eventually have a non-equidistant spacing.