Worked on the junit5 repository to deliver a focused code refactor aimed at improving the readability and performance of internal collection updates. The approach involved replacing Arrays.asList() with Collections.addAll() in several core locations, which eliminated unnecessary intermediate list creation and reduced allocations. This change resulted in simpler, more maintainable code paths while preserving explicit validation to ensure correctness. The refactor also removed redundant imports and casts, streamlining the codebase without altering behavior. Demonstrated proficiency in Java and code refactoring, collaborating with other contributors to maintain code quality and consistency throughout the update, ultimately closing a targeted issue in the project.