SMOGN with under_samp=False fails to return original data

[eschibli]

Hello devs,

I have a small amount of data and need to oversample outliers without undersampling my original data. However, running SMOGN with under_samp=False appears to return only the synthetic data. This can easily be worked around by concating the output to the original data, but it is extremely unintuitive, doesn't seem to be documented anywhere, and is not conducive to including SMOGN in a larger pipeline.

is this behaviour intended?

Colab example here