Describe the PR

• This adds a unit test to verify the rule UnusedMethod actually works.
• This is important, as that actually tests the integration with apexlink

I could now confirm, that #4453 is indeed fixed by the update of apexlink (#4528) - since apexlink now hardcoded uses always UTF-8 - for both itself and when creating a antlr char stream (see https://github.com/nawforce/apex-link/blob/7688adcb7a2d7f8aa28d0618ffb2a3aa81151858/pkgforce/jvm/src/main/scala/com/nawforce/runtime/parsers/SourceData.scala#L55-L59 )

I couldn't create a unit test to reproduce #4453, since that would have involved changed the default charset in java in a running vm which is not possible.

But I manually verified, that #4453 is now fixed.

Related issues

• Fixes [apex] [7.0-rc1] Exception while initializing Apexlink (Index 34812 out of bounds for length 34812) #4453

Ready?

• Added unit tests for fixed bug/feature
• Passing all unit tests
• Complete build ./mvnw clean verify passes (checked automatically by github actions)
• Added (in-code) documentation (if needed)