code: def is_model_mpttmeta_subclass(node):
      
      if node.name != 'MPTTMeta' or not isinstance(node.parent, ClassDef):
          return False
  
      parents = ('django.db.models.base.Model',
                 '.Model',  # for the transformed version used in this plugin
                 'django.forms.forms.Form',
                 '.Form',
                 'django.forms.models.ModelForm',
                 '.ModelForm')
      return node_is_subclass(node.parent, *parents)
docs: Checks that node is derivative of MPTTMeta class.