'Check an OpenID message and its openid.return_to value
against a return_to URL from an application.  Return True on
success, False on failure.'

def _checkReturnTo(self, message, return_to):

    try:
        self._verifyReturnToArgs(message.toPostArgs())
    except ProtocolError as why:
        oidutil.log(('Verifying    return_to    arguments:    %s' % (why[0],)))
        return False
    msg_return_to = message.getArg(OPENID_NS, 'return_to')
    app_parts = urlparse(urinorm.urinorm(return_to))
    msg_parts = urlparse(urinorm.urinorm(msg_return_to))
    for part in range(0, 3):
        if (app_parts[part] != msg_parts[part]):
            return False
    return True
