anchor.diff:  public interface SopDocumentContentRepository extends ContentRepository<SopDocument, UUID>, Renderable<SopDocument> {
   }
   ----
  -
   . Set up Spring to create proxy instances for these two interfaces using JavaConfig:
   +
   [source, java]
  
positive.code: The central interface in the Spring Content is the `ContentRepository` abstraction.  This interface provides CRUD functionality and metadata association for content.  It is typed to the Spring Data domain class, with which the content will be associated, and to content id type of that domain class. 
  
  [[content-repositories.repository]]
  +
  .ContentRepository interface
  ====
  [source, java]
  
negative.code: Content repositories can therefore optionally also be given rendition capabilities by extending the `Renderable<E>` interface.
  
  [source, java]
  .Renderable interface
  ----
  public interface Renderable<E> {
  