code: def clean(self, user=None):
          
          doc = self._resource
          internal_fields = deepcopy(self.internal_fields)
          if user is None or not user.is_user(self.organisation_id):
              internal_fields.append('permissions')
  
          result = {k: v for k, v in doc.iteritems() if k not in internal_fields}
  
          return result
docs: Remove internal fields