'Pre-process incoming XML stanzas by converting any
``\'jabber:client\'`` namespaced elements to the component\'s
default namespace.
:param xml: The XML stanza to pre-process.'

def incoming_filter(self, xml):

    if xml.tag.startswith('{jabber:client}'):
        xml.tag = xml.tag.replace('jabber:client', self.default_ns)
    return xml
