code: def validate(self):
          '''Validate that devices are each trusted by one another
  
          :param kwargs: dict -- keyword args for devices and partition
          :raises: DeviceNotTrusted
          '''
  
          self._populate_domain()
          missing = []
          for domain_device in self.domain:
              for truster, trustees in iteritems(self.domain):
                  if domain_device not in trustees:
                      missing.append((domain_device, truster, trustees))
  
          if missing:
              msg = ''
              for item in missing:
                  msg += '\n%r is not trusted by %r, which trusts: %r' % \
                      (item[0], item[1], item[2])
              raise DeviceNotTrusted(msg)
          self.device_group = DeviceGroup(
              devices=self.devices,
              device_group_name=self.device_group_name,
              device_group_type=self.device_group_type,
              device_group_partition=self.partition
          f validate(self):
          '''Validate that devices are each trusted by one another
  
          :param kwargs: dict -- keyword args for devices and partition
          :raises: DeviceNotTrusted
          '''
  
          self._populate_domain()
          missing = []
          for domain_device in self.domain:
              for truster, trustees in iteritems(self.domain):
                  if domain_device not in trustees:
                      missing.append((domain_device, truster, trustees))
  
          if missing:
              msg = ''
              for item in missing:
                  msg += '\n%r is not trusted by %r, which trusts: %r' % \
                      (item[0], item[1], item[2])
              raise DeviceNotTrusted(msg)
          self.device_group = DeviceGroup(
              devices=self.devices,
              device_group_name=self.device_group_name,
              device_group_type=self.device_group_type,
              device_group_partition=self.partition
          )
docs: Validate that devices are each trusted by one another
  
          :param kwargs: dict -- keyword args for devices and partition
          :raises: DeviceNotTrusted