human
Here's a good function header given the following:
I wrote the below code

    if (auth.permission.format != 's3json'):
        return ''
    def prep(r):
        if (r.method != 'options'):
            return False
        return True
    s3.prep = prep
    return s3_rest_controller()

What's a good function header?
assistant
#Here's a good function header.

def activity_type_sector():