A convenience method to obtain the extension element used
           as the address binding for the port.

def getAddressBinding(self):
        """A convenience method to obtain the extension element used
           as the address binding for the port."""
        for item in self.extensions:
            if isinstance(item, SoapAddressBinding) or \
               isinstance(item, HttpAddressBinding):
                return item
        raise WSDLError(
            'No address binding found in port.'
            )