Worked on enhancing the stability of the FAISS Python Class Wrappers in the facebookresearch/faiss repository by addressing a specific bug related to NumPy array handling. Focused on Python development and bug fixing, the work involved replacing a generic truthiness check on the variable D with an explicit check for D being not None. This adjustment prevented a TypeError that could occur when D was a NumPy array, ensuring more robust conditional logic. The solution aligned with established error-handling patterns in the codebase and incorporated review feedback, ultimately improving reliability for downstream users and integrations relying on these Python wrappers.