unittest case testIssue50 run error ORA-24816 against db charset "JA16EUC"

[zhua03]

1. What versions are you using?

DB version 19.8.0.0.0 , with db charset JA16EUC
cx_Oracle.version: 8.0.1
cx_Oracle.clientversion: (19, 8, 0, 0, 0)

2. Describe the problem

test ”testIssue50“ run error ORA-24816 , when db charset is JA16EUC. (test case pass with db charset JA16SJIS)

but this test case comment: "test issue 50 - avoid error ORA-24816"

3. Include a runnable Python script that shows the problem.

command line to run test case:
python -u unittest StringVar.TestCase.testIssue50