namespaceURI -- namespace of element
            localName -- local name of element

def checkNode(self, namespaceURI=None, localName=None):
        '''
            namespaceURI -- namespace of element
            localName -- local name of element
        '''
        namespaceURI = namespaceURI or self.namespaceURI
        localName = localName or self.name
        check = False
        if localName and self.node:
            check = self._dom.isElement(self.node, localName, namespaceURI)
        if not check:
            raise NamespaceError, 'unexpected node type %s, expecting %s' %(self.node, localName)