human
Give me a the Python code you requested given the following:
Complete the below
def group_membership():

    ''''RESTful CRUD controller for options.s3json lookups'
    '''
assistant
#Here is the Python code you requested.
    if (auth.permission.format != 's3json'):
        return ''
    def prep(r):
        if (r.method != 'options'):
            return False
        return True
    s3.prep = prep
    return s3_rest_controller()