No module named 'frida.application'

[CCint3]

'frida.application' is imported in examples/child_gating.py! but not found in my frida python.

$ pip list | grep frida
frida              16.0.2
frida-dexdump      1.0.3
frida-tools        12.0.1

$ python --version              
Python 3.8.9 

[CCint3]

sorry, now 'examples/child_gating.py' change to from frida_tools.application import Reactor in new version!