'unregister protocol: reverses the effects of Òregister protocolÓ
Required argument: Application sig.
Keyword argument for_protocol: protocol prefix. If none, unregister for all protocols
Keyword argument _attributes: AppleEvent attribute dictionary
Returns: TRUE if successful'

def unregister_protocol(self, _object=None, _attributes={}, **_arguments):

    _code = 'WWW!'
    _subcode = 'UNRP'
    aetools.keysubst(_arguments, self._argmap_unregister_protocol)
    _arguments['----'] = _object
    (_reply, _arguments, _attributes) = self.send(_code, _subcode, _arguments, _attributes)
    if _arguments.get('errn', 0):
        raise aetools.Error, aetools.decodeerror(_arguments)
    if _arguments.has_key('----'):
        return _arguments['----']
