API setfenv

Modifies the environment associated with a function. f = setfenv(f, env)

• f: or - A function to modify the environment of, or a numeric level of a function on the call stack starting from 1.
• env: - The environment to be assigned to the function.

• f: - The function whose environment was modified.

• This function will raise an error if the function to be modified has an existing environment whose metatable has an field set.
• If this function is called insecurely and the modified function is a Lua function, the modified function will be irrevocably tainted. This will result in all future calls to the function tainting execution.