Keyword arguments:
            namespaceURI -- namespace of attribute
            qualifiedName -- qualified name of new attribute value
            value -- value of attribute

def _setAttributeNS(self, namespaceURI, qualifiedName, value):
        '''
        Keyword arguments:
            namespaceURI -- namespace of attribute
            qualifiedName -- qualified name of new attribute value
            value -- value of attribute
        '''
        self.node.setAttributeNS(namespaceURI, qualifiedName, value)