text: from . import models
  
  from rest_framework import serializers
  
  
  class BookSerializer(serializers.ModelSerializer):
  
      class Meta:
          model = models.Book
          fields = (
              'pk', 
              'title', 
              'author', 
              'category', 
              'isbn', 
          )
  
  
  class IssueSerializer(serializers.ModelSerializer):
  
      class Meta:
          model = models.Issue
          fields = (
              'pk', 
              'shelf_id', 
              'available_status', 
          )
  
  
  class LogSerializer(serializers.ModelSerializer):
  
      class Meta:
          model = models.Log
          fields = (
              'pk', 
              'issued_at', 
              'return_time', 
          )
  
  
  