How to use the micawber.compat.get_charset function in micawber

def fetch(request, timeout=None):
    urlopen_params = {}
    if timeout:
        urlopen_params['timeout'] = timeout
    resp = urlopen(request, **urlopen_params)
    if resp.code < 200 or resp.code >= 300:
        return False

    # by RFC, default HTTP charset is ISO-8859-1
    charset = get_charset(resp) or 'iso-8859-1'

    content = resp.read().decode(charset)
    resp.close()
    return content