bugs.gh_7243_test
Some UNICODE characters can lead to wrong CONTAINING evaluation when lower/upper uses different number of bytes in its encoding
  UTC 2023.02.22 19:10 pavel-zotov
  Added/Updated tests\bugs\gh_7243_test.py: Cheched on 5.0.0.958; 4.0.3.2903 - all fine.
  https://github.com/FirebirdSQL/firebird-qa/commit/beec9beb53295059b82805c8f33aaae0b6b162f5