anchor.diff:      UserInfo3 = #{uid => UserId3},
       CredState = <<"some_cred">>,
       Cred = <<"secret">>,
  -    MeckModules = [tts_data_sqlite, tts_cred_sup, tts_cred_worker],
  +    MeckModules = [tts_data_sqlite, tts_cred_sup, tts_cred_worker, tts_service],
       Token = #{},
       Params = [],
       MyPid = self(),
  -    AddFun = fun(User, Service, State) ->
  +    Interface = <<"test interface">>,
  +    AddFun = fun(User, Service, IFace, State) ->
  +                     IFace = Interface,
                        User = UserId1,
                        Service = ServiceId,
                        State = CredState,
  
positive.code:     UserInfo3 = #{uid => UserId3},
      UserInfo4 = #{uid => UserId4},
      CredState = <<"some_cred">>,
      Cred = <<"secret">>,
      MeckModules = [tts_data_sqlite, tts_cred_sup, tts_cred_worker],
      MyPid = self(),
      GetFun = fun(UserId) ->
                       case UserId of
                           UserId1 -> {ok, [{ServiceId, CredState}]};
                           UserId2 -> {ok, [{ServiceId, CredState}]};
                           UserId3 -> {ok, [{ServiceId, CredState}]};
                           _ -> {ok, []}
                       end
               end,
      DelFun = fun(UserId, Service, State) ->
                       Service = ServiceId,
                       State = CredState,
                       case UserId of
                           UserId1 -> ok;
                           UserId2 -> ok;
  
negative.code:                          #{uid := User} = UserInfo,
                           Pid = MyPid,
                           case User of
                               UserId1 -> {ok, #{result => RevokeResult,
                                                state => CredState}, []};
                               UserId2 -> {ok, #{
                                             result => RevokeResult,
                                             error => <<>>}, []};
                               _ -> {error, just_because, []}
                           end
  