anchor.diff:  
   
   
  -%% Initialize state
  +%% @doc Initialize state
   %%
   initial_state() ->
  -    #state{type = set}.
  +    #state{}.
   initial_state(Type) ->
       #state{type = Type}.
   
   
  -%% Command
  +%% @doc Command
   %%
   command(_S) ->
       Cmd0 = [{call, leo_backend_db_api, put,    [?INSTANCE_NAME, key(), value()]},
  
positive.code:     oneof(Cmd0).
  
  
  %% Pre-Condition
  %%
  precondition(_S, {call,_,_,_}) ->
      true.
  
  
  %% Next-State
  %%
  next_state(S, _V, {call,_,put,[_Instance, Key,_Object]}) ->
      case proplists:is_defined(Key, S#state.stored) of
          false ->
              S#state{stored = S#state.stored ++ [Key]};
  
negative.code:                         end, lists:seq(0, 9))).
  
  
  %% @doc Utils
  %%
  key() ->
      frequency([{1, elements(?KEYS)}]).
  