[help wanted] test coverage for vital components

[kartva]

Currently, the following test classes in the repository are lacking proper tests:

• ThreadDiskIO.java
• HeapMetricsTest.java
• ThreadListTest.java
• GCMetricsTest.java

Writing unit tests is a great way to become familiar with the codebase and offers a pathway to contributing to OpenSearch. Learning to write good tests is also valuable skill that you can develop by working on this issue.

For examples of current unit tests, you can have a look at #47 or #54.

If you would like to work on any of these, leave a comment on this issue with the name of the test so everyone knows you're working on it!

[dblock]

[Triage -- attendees 1, 2, 3, 4, 5, 6, 7]

@DesmondWillowbrook Any interest in adding the missing tests?

[kartva]

I will not have any free time in the immediate future to work on this project. @dblock