'unregister viewer: Revert to the old way of handling this MIME type
Required argument: Application sig
Keyword argument MIME_type: MIME type to be unregistered
Keyword argument _attributes: AppleEvent attribute dictionary
Returns: TRUE if the event was successful'

def unregister_viewer(self, _object, _attributes={}, **_arguments):

    _code = 'WWW!'
    _subcode = 'UNRV'
    aetools.keysubst(_arguments, self._argmap_unregister_viewer)
    _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['----']
