Missing compression methods that seemed to work previously

Hi,
I intended to use [snapista](https://github.com/snap-contrib/snapista) which is using snappy:

$ grep -R 'from snappy'
src/snapista/graph.py:from snappy import GPF
src/snapista/operatorparams.py:from snappy import GPF
src/snapista/operator.py:from snappy import GPF, jpy

but unfortunately neither GPF nor jpy are working:

$ python3
Python 3.11.2 (main, Mar 13 2023, 12:18:29) [GCC 12.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from snappy import GPF
Traceback (most recent call last):
File "", line 1, in
ImportError: cannot import name 'GPF' from 'snappy' (/usr/lib/python3/dist-packages/snappy/__init__.py)
>>> from snappy import jpy
Traceback (most recent call last):
File "", line 1, in
ImportError: cannot import name 'jpy' from 'snappy' (/usr/lib/python3/dist-packages/snappy/__init__.py)

I've found [some website](https://forum.step.esa.int/t/slower-snappy-processing/6354/5) mentioning even more compression methods (`ProductIO` and `HashMap`) which also do not work in version 0.6.1 which I tried (I also tried version 0.5.3 with same result). Am I missing something in my setup or is the code using snappy in this way outdated?

Kind regards, Andreas.