Create a custom transformation before feature extraction

[njellinas]

I have a CutSet and I want to define a custom Resampler, for example a neural model that performs bandwidth extension from 16 kHz to 24 kHz and then extract features.
Or in general create a transformation that will be applied to the CutSet in a similar way to .resample, .perturb_volume etc.
I found that there is no easy way to do this, there is no documentation as to how you apply transforms to the recordings apart from the predefined ones.