Python: dict_decode throws error when 3rd dimension = 'absent','reserved1','reserved2'

[RenoFilla]

None of the following works running in dict_decode:

'BGgwjuyDg8wzcgkh9Bgkh9Bgkh9Bgkh9B' (absent)
'BmGgwjuyDg8wzc8Bgkh9Bgkh9BTgkh9Bgkh9BgF' (reserved1)
'B2GgwjuyDg8wzc8Bgkh9Bgkh9BTgkh9Bgkh9BgF' (reserved2)

---

KeyError Traceback (most recent call last)
~\AppData\Local\Temp\ipykernel_27848\2616460968.py in
----> 1 fp.dict_decode(p)

C:\Tools\Programming\Anaconda3\lib\site-packages\flexpolyline_init_.py in dict_decode(encoded)
42 """Return an list of coordinates dicts. The dict contains always the keys 'lat', 'lng' and
43 depending on the polyline can contain a third key ('elv', 'lvl' or 'alt')."""
---> 44 return list(iter_dict_decode(encoded))

C:\Tools\Programming\Anaconda3\lib\site-packages\flexpolyline_init_.py in iter_dict_decode(encoded)
30 """Return an iterator over coordinates dicts. The dict contains always the keys 'lat', 'lng' and
31 depending on the polyline can contain a third key ('elv', 'lvl', 'alt', ...)."""
---> 32 third_dim_key = THIRD_DIM_MAP[get_third_dimension(encoded)]
33 for row in iter_decode(encoded):
34 yield {

KeyError: 0