sw -- SoapWriter instance, add WS-Address header.

def serialize(self, sw, **kw):
        '''
        sw -- SoapWriter instance, add WS-Address header.
        '''
        for pyobj in self.header_pyobjs:
            if hasattr(pyobj, 'typecode') is False:
                raise RuntimeError, 'all header pyobjs must have a typecode attribute'

            sw.serialize_header(pyobj, **kw)