anchor.diff:                     , Unexpected
                      , Callbacks
                      );
  +
   %% Expected some Type
   validate( ParentKey
           , {Type, Options} = _E
  
positive.code:     _ ->
        {not_equal, {Key, E, A}}
    end;
  %% Otherwise
  validate_primitive(Key, E, A, _Callbacks) ->
    {not_equal, {Key, E, A}}.
  
negative.code:                               , Unexpected
                                , Callbacks
                                );
  
  %% Expected something else
  validate(ParentKey, E, A, Unexpected, Callbacks) ->
    validate_simple(ParentKey, E, A, Unexpected, Callbacks).
  