docs: def clean(self, *args, **kwargs):
          """
          Check if comments can be inserted for parent node or parent layer
          """
          # check done only for new nodes!
          if not self.pk:
              node = self.node
              # ensure comments for this node are allowed
              if node.participation_settings.comments_allowed is False:
                  raise ValidationError("Comments not allowed for this node")
              # ensure comments for this layer are allowed
              if 'nodeshot.core.layers' in settings.INSTALLED_APPS:
                  layer = node.layer
                  if layer.participation_settings.comments_allowed is False:
                      raise ValidationError("Comments not allowed for this layer")