code: def change(self, event):
          
  
          try:
              data, schema, user, client = self._get_args(event)
          except AttributeError:
              return
  
          try:
              uuid = data['uuid']
              change = data['change']
              field = change['field']
              new_data = change['value']
          except KeyError as e:
              self.log("Update request with missing arguments!", data, e,
                       lvl=critical)
              self._cancel_by_error(event, 'missing_args')
              return
  
          storage_object = None
  
          try:
              storage_object = objectmodels[schema].find_one({'uuid': uuid})
          except Exception as e:
              self.log('Change for unknown object requested:', schema, data, lvl=warn)
  
          if storage_object is None:
              self._cancel_by_error(event, 'not_found')
              return
  
          if not self._check_permissions(user, 'write', storage_object):
              self._cancel_by_permission(schema, data, event)
              return
  
          self.log("Changing object:", storage_object._fields, lvl=debug)
          storage_object._fields[field] = new_data
  
          self.log("Storing object:", storage_object._fields, lvl=debug)
          try:
              storage_object.validate()
          except ValidationError:
              self.log("Validation of changed object failed!",
                       storage_object, lvl=warn)
              self._cancel_by_error(event, 'invalid_object')
              return
  
          storage_object.save()
  
          self.log("Object stored.")
  
          result = {
              'component': 'hfos.events.objectmanager',
              'action': 'change',
              'data': {
                  'schema': schema,
                  'uuid': uuid
              }
          }
  
          self._respond(None, result, event)
docs: Change an existing object