anchor.diff:  gets the return value from the resolver it merges it back into the context entities, making all data
   returned from the resolver available to access new attributes as needed.
   
  -== `index-io`
  +== index-io
   
   [source,clojure]
   ----
  
positive.code: attributes `:product/brand` and `:product/brand-id`. And this is how autocomplete is
  done via the `index-io`.
  
  == `index-attributes`
  
  [source,clojure]
  ----
  
negative.code: ;     ::pc/resolve (fn ...)}
  ----
  
  == index-mutations
  
  This index contains the mutation definitions, its similar to the `index-resolvers`.
  
  == index-oir
  
  [source,clojure]
  ----
  