- "href": "https://example.com/api/books/grandchild/",
- "pdf": "",
- "txt": "https://example.com/media/txt/grandchild.txt",
+ "href": "http://testserver/api/books/grandchild/",
+ "pdf": "http://testserver/media/pdf/grandchild.pdf",
+ "txt": "http://testserver/media/txt/grandchild.txt",