code: def json(self, validate=True, *args, **kwargs):
          
          if validate:
              self.validate()
          # automatically adds NetJSON type
          config = deepcopy(self.config)
          config.update({'type': 'DeviceConfiguration'})
          return json.dumps(config, *args, **kwargs)
docs: returns a string formatted as **NetJSON DeviceConfiguration**;
          performs validation before returning output;
  
          ``*args`` and ``*kwargs`` will be passed to ``json.dumps``;
  
          :returns: string