Error while importing wbi_core

[versant2612]

Successfully installed ujson-5.2.0 wikibaseintegrator-0.12.0rc4
....

from wikibaseintegrator import wbi_core

ImportError: cannot import name 'wbi_core' from 'wikibaseintegrator' (/usr/local/lib/python3.9/dist-packages/wikibaseintegrator/init.py)