text: from django.db import models
  from django.utils import timezone
  from django.contrib.auth.models import User
  from django_url_short.settings import LINK_EXPIRATION_DELTA
  
  
  class LinkDestination(models.Model):
      user = models.ForeignKey(User, on_delete=models.CASCADE)
      created_on = models.DateTimeField(auto_now_add=True, editable=True)
      destination = models.CharField(max_length=2500, null=False)
      link = models.CharField(max_length=25, unique=True, null=False)
      clicks = models.BigIntegerField(default=0)
  
      def __str__(self):
          return f'{self.id}'
  
      @property
      def expires_on(self):
          return self.created_on + LINK_EXPIRATION_DELTA
  
      @property
      def expired(self):
          return self.expires_on <= timezone.now()