anchor.diff:      RecipientId = aec_id:create(account, <<Recipient:256>>),
       Callback = fun(API, ChainState) ->
                          API:spend(RecipientId, Value, ChainState) end,
  -    call_chain(Callback, State).
  +    cast_chain(Callback, State).
   
   %% ------------------------------------------------------------------
   %% Oracle operations.
  
positive.code:             [_, _, Sign, R] = get_args(ArgumentTypes, Data),
              QueryKey = <<Query:256>>,
              Callback = fun(API, ChainState) -> API:oracle_respond(OracleKey, QueryKey, Sign, R, ChainState) end,
              call_chain(Callback, State);
          {error, _} = Err -> Err
      end.
  
  
negative.code:     ArgumentTypes = [word, word, oracle_ttl_t()],
      [Oracle, Sign, TTL] = get_args(ArgumentTypes, Data),
      Callback = fun(API, ChainState) -> API:oracle_extend(<<Oracle:256>>, Sign, TTL, ChainState) end,
      cast_chain(Callback, State).
  
  
  oracle_call_get_answer(_Value, Data, State) ->
  