docs: def _apply_cell_filters(self, context):
          """
          Applies the field restrictions based on the
           return value of the context's "has_permission()" method.
           Stores them on self._unpermitted_fields.
  
          Returns:
              List of unpermitted fields names.
          """
          self.setattrs(_is_unpermitted_fields_set=True)
          for perm, fields in self.Meta.field_permissions.items():
              if not context.has_permission(perm):
                  self._unpermitted_fields.extend(fields)
          return self._unpermitted_fields