old_contents: from enum import Enum
  
  from odin import new_resources
  
  
  class Genre(Enum):
      ScienceFiction = "sci-fi"
      Fantasy = "fantasy"
      Biography = "biography"
      Others = "others"
      ComputersAndTechnology = "computers-and-tech"
  
  
  class Book(new_resources.NewResource):
      class Meta:
          key_field_name = "isbn"
  
      title: str
      isbn: str
      num_pages: int
      rrp: float = 20.4
      fiction: bool
      genre: Genre
      published: List[datetime]
      authors: List[Author]
      publisher: Optional[Publisher] = None
  
new_contents: from datetime import date
  from enum import Enum
  from typing import List, Optional
  
  from odin import new_resources
  from .resources import Author, Publisher
  
  
  class Genre(Enum):
      ScienceFiction = "sci-fi"
      Fantasy = "fantasy"
      Biography = "biography"
      Others = "others"
      ComputersAndTechnology = "computers-and-tech"
  
  
  class Book(new_resources.NewResource):
      class Meta:
          key_field_name = "isbn"
  
      title: str
      isbn: str
      num_pages: int
      rrp: float = 20.4
      fiction: bool
      genre: Genre
      published: List[date]
      authors: List[Author]
      publisher: Optional[Publisher] = None
  
subject: Update sample new resource