anchor.diff:  default_update(ObjectRec, CallbackFun) ->
       QueryName = chef_object:update_query(ObjectRec),
       UpdatedFields = chef_object:fields_for_update(ObjectRec),
  -    CallbackFun(QueryName, UpdatedFields).
  +    CallbackFun({QueryName, UpdatedFields}).
  
positive.code: 
  -type update_return() :: {ok, 1} | {ok, not_found} | {error, _}.
  
  -type update_callback() :: fun((UpdateQueryName :: atom(), BindParameters :: list()) ->
                                        update_return()).
  
  
  -callback authz_id(object_rec()) -> object_id().
  -callback is_indexed() -> boolean().
  
negative.code: -callback record_fields() -> list(atom()).
  -callback list(object_rec(), select_callback()) -> select_return().
  -callback fetch(object_rec(), select_callback()) -> select_return().
  -callback update(object_rec(), select_callback()) ->
       update_return().
      
  
  