cannot import name 'ParamSpec' from 'typing'

[bluelemonade]

after installing with pip on a Pi4 with buster the simple video_file.py throws

bin/python3 /home/pi/ravidplay/python-omxplayer-wrapper/examples/video_file.py
Traceback (most recent call last):
File "/home/pi/ravidplay/python-omxplayer-wrapper/examples/video_file.py", line 3, in
from omxplayer.player import OMXPlayer
File "/usr/local/lib/python3.7/dist-packages/omxplayer_wrapper-0.3.3-py3.7.egg/omxplayer/init.py", line 1, in
File "/usr/local/lib/python3.7/dist-packages/omxplayer_wrapper-0.3.3-py3.7.egg/omxplayer/player.py", line 25, in
File "/usr/local/lib/python3.7/dist-packages/evento-2.0.1-py3.7.egg/evento/init.py", line 2, in
from .decorators import (
File "/usr/local/lib/python3.7/dist-packages/evento-2.0.1-py3.7.egg/evento/decorators.py", line 4, in
from .signature import AsyncSignatureEvent, P, R, SignatureEvent
File "/usr/local/lib/python3.7/dist-packages/evento-2.0.1-py3.7.egg/evento/signature.py", line 1, in
from typing import (
ImportError: cannot import name 'ParamSpec' from 'typing' (/usr/lib/python3.7/typing.py)