'Populate the stanza object using an optional XML object.
Overrides ElementBase.setup.
Sets a default error type and condition, and changes the
parent stanza\'s type to \'error\'.
Arguments:
xml -- Use an existing XML object for the stanza\'s values.'

def setup(self, xml=None):

    if ElementBase.setup(self, xml):
        self['type'] = 'cancel'
        self['condition'] = 'feature-not-implemented'
    if (self.parent is not None):
        self.parent()['type'] = 'error'
