[Improvement] No need for test methods to be public

### What would you like to be improved?

No need for test methods to be public and we have a mixture of some that are and some that are not.

### How should we improve?

Remove public from test methods.

Search the repository's test sources for test methods declared public and inspect the surrounding test classes for the existing mixture. Remove the public modifier from applicable test methods, then run the relevant test suite to confirm all tests still pass and no public test methods remain.

Written by the indexing model from the issue text.