code: def attach_ip(self, server, family='IPv4'):
          
          body = {
              'ip_address': {
                  'server': str(server),
                  'family': family
              }
          }
  
          res = self.request('POST', '/ip_address', body)
          return IPAddress(cloud_manager=self, **res['ip_address'])
docs: Attach a new (random) IPAddress to the given server (object or UUID).