如何在Django中完成文本的完整历史记录？

from django.db import models
from django.contrib.contenttypes.fields import GenericForeignKey
from django.contrib.contenttypes.models import ContentType

class History(models.Model):
    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
    object_id = models.PositiveIntegerField()
    content_object = GenericForeignKey('content_type', 'object_id')
    text = models.TextField()
    created_at = models.DateTimeField(auto_now_add=True)

from django.db import models

class MyModel(models.Model):
    name = models.CharField(max_length=100)
    current_text = models.TextField()

from django.db.models.signals import pre_save
from django.dispatch import receiver

@receiver(pre_save, sender=MyModel)
def create_history(sender, instance, **kwargs):
    if instance.pk:
        old_instance = MyModel.objects.get(pk=instance.pk)
        if old_instance.current_text != instance.current_text:
            History.objects.create(
                content_object=instance,
                text=old_instance.current_text
            )

my_model_instance = MyModel.objects.get(id=1)
histories = History.objects.filter(content_object=my_model_instance).order_by('-created_at')