          """
          self.m2m_data = {}
  
          if instance is not None:
              for key, val in attrs.items():
                  setattr(instance, key, val)
 
</s>
        self.related_data = {}
          """
          self.m2m_data = {}
        self.related_data = {}
  
          if instance is not None:
              for key, val in attrs.items():
                  setattr(instance, key, val)
keep add keep keep keep keep
 ManyPrimaryKeyRelatedField now supports create for one-to-many rel
rest_framework/serializers.py