anchor.diff:  get_update_metadata(#riakc_obj{updatemetadata=UM}=Object) ->
       case UM of
           undefined ->
  -            try
  -                get_metadata(Object)
  -            catch 
  -                throw:no_metadata ->
  -                    dict:new()
  -            end;
  +            get_metadata(Object);
           UM ->
               UM
       end.
  
positive.code: 
  %% @doc Return the content type of the value if there are no siblings.
  %% @see get_metadata/1
  %% @throws siblings | no_metadata
  -spec get_content_type(Object::riakc_obj()) -> content_type().
  get_content_type(Object=#riakc_obj{}) ->
      UM = get_metadata(Object),
  
negative.code:     ?assertEqual([], get_metadatas(O)),
      ?assertEqual([], get_values(O)),
      ?assertEqual([], get_contents(O)),
      ?assertThrow(no_value, get_value(O)).    
  
  contents0_test() ->
  