'Make sure we have the pre-requisites.'

def check_for_setup_error(self):

    if ((not self.configuration.disco_rest_ip) and (self.configuration.disco_choice_client.lower() == 'rest')):
        msg = _('Could    not    find    the    IP    address    of    the    REST    server.')
        raise exception.VolumeBackendAPIException(data=msg)
    else:
        path = self.configuration.disco_wsdl_path
        if (not os.path.exists(path)):
            msg = _('Could    not    find    DISCO    wsdl    file.')
            raise exception.VolumeBackendAPIException(data=msg)
