luxon: DateTime.toFormat('ZZZZ') not showing expected output

According to the docs, when the ‘ZZZZ’ token is passed in the format string, the abbreviated named offset string should be displayed in the output string. However, the timezone offset from GMT is being displayed instead.

Code snippet to test the issue:

DateTime.fromISO("2019-05-03T10:59:22Z")
.setZone("America/Los_Angeles")
.toFormat('dd-MMM-yy hh:mm:ss ZZZZ');

Expected Output:

03-May-19 03:59:22 PDT

Actual Output:

03-May-19 03:59:22 GMT-7

Package Version: ^1.13.0

Environments: node@12.1.0, Chrome