⚠ simulated AI-generated code
This code is framed as if an AI coding assistant wrote it, and has a realistic issue AI assistants actually produce — sometimes a real bug, sometimes code that runs fine but is more complicated or less idiomatic than it needs to be. It is not from a real model call. Read it like you'd review any AI suggestion — don't assume it's correct, or well-written, just because it looks polished.
An AI coding assistant wrote remove_duplicates(nums) to strip duplicate values from a list while keeping the order of first appearance. It looks clean and the comment sounds confident — but read the loop carefully.
fix this code so it matches
remove_duplicates([1, 2, 1, 3]) is [1, 2, 3]. remove_duplicates([1, 2, 3]) is [1, 2, 3] (no duplicates, unchanged).