Worked on the yhyang201/sglang repository to address a critical bug in the HiCache subsystem, focusing on the caching logic within the TreeNode data structure. Improved correctness and reliability by removing the lru_cache decorator from the get_prefix_hash_values method, ensuring that each call returns a fresh list and preventing unintended mutations or cross-call data sharing. Developed comprehensive unit tests in Python to verify that returned lists are not shared, thereby enhancing the stability of hash value computation and overall maintainability. Demonstrated strong skills in bug fixing, data structure management, and unit testing, contributing to more robust caching behavior.