如何在django-rest-framework中序列化具有自定义关系的2个模型？

from django.db import models

class Author(models.Model):
    name = models.CharField(max_length=100)

class Book(models.Model):
    title = models.CharField(max_length=100)
    author = models.ForeignKey(Author, on_delete=models.CASCADE)

from rest_framework import serializers

class AuthorSerializer(serializers.ModelSerializer):
    class Meta:
        model = Author
        fields = '__all__'

class BookSerializer(serializers.ModelSerializer):
    author = AuthorSerializer()

    class Meta:
        model = Book
        fields = '__all__'

from rest_framework import viewsets

class AuthorViewSet(viewsets.ModelViewSet):
    queryset = Author.objects.all()
    serializer_class = AuthorSerializer

class BookViewSet(viewsets.ModelViewSet):
    queryset = Book.objects.all()
    serializer_class = BookSerializer