old_contents: from django.db import models
  
  # Create your models here.
  
  
  class Category(models.Model):
      name = models.CharField(max_length=300, unique=True)
      slug = models.SlugField(max_length=50, unique=True)
  
      class Meta:
          abstract = True
          ordering = ('name',)
  
  
      def __str__(slef):
          return self.name
  
new_contents: from django.db import models
  
  # Create your models here.
  
  
  class Category(models.Model):
      name = models.CharField(max_length=300, unique=True)
      slug = models.SlugField(max_length=50, unique=True)
  
      class Meta:
          abstract = True
          ordering = ('name',)
  
  
      def __str__(self):
          return self.name
  
subject: Fix typo in Category Class #24