anchor.diff:  
   -spec wait_for_confirm(Event :: timeout | term(), StateData :: #statedata{}) ->
   	Result :: {next_state, NextStateName :: atom(), NewStateData :: #statedata{}}
  -		| {next_state, NextStateName :: atom(), NewStateData :: #statedata{}, Timeout :: non_neg_integer() | infinity}
  +		| {next_state, NextStateName :: atom(), NewStateData :: #statedata{},
  +		Timeout :: non_neg_integer() | infinity}
   		| {next_state, NextStateName :: atom(), NewStateData :: #statedata{}, hibernate}
   		| {stop, Reason :: normal | term(), NewStateData :: #statedata{}}.
   %% @doc Handle events sent with {@link //stdlib/gen_fsm:send_event/2.
  
positive.code: -spec handle_sync_event(Event :: term(), From :: {Pid :: pid(), Tag :: term()},
  		StateName :: atom(), StateData :: #statedata{}) ->
  	Result :: {reply, Reply :: term(), NextStateName :: atom(), NewStateData :: #statedata{}}
  		| {reply, Reply :: term(), NextStateName :: atom(), NewStateData :: #statedata{}, Timeout :: non_neg_integer() | infinity}
  		| {reply, Reply :: term(), NextStateName :: atom(), NewStateData :: #statedata{}, hibernate}
  		| {next_state, NextStateName :: atom(), NewStateData :: #statedata{}}
  		| {next_state, NextStateName :: atom(), NewStateData :: #statedata{}, Timeout :: non_neg_integer() | infinity}
  		| {next_state, NextStateName :: atom(), NewStateData :: #statedata{}, hibernate}
  		| {stop, Reason :: normal | term(), Reply :: term(), NewStateData :: #statedata{}}
  		| {stop, Reason :: normal | term(), NewStateData :: #statedata{}}.
  
negative.code: 
  -spec handle_info(Info :: term(), StateName :: atom(), StateData :: #statedata{}) ->
  	Result :: {next_state, NextStateName :: atom(), NewStateData :: #statedata{}}
  		| {next_state, NextStateName :: atom(), NewStateData :: #statedata{},
  		Timeout :: non_neg_integer() | infinity}
  		| {next_state, NextStateName :: atom(), NewStateData :: #statedata{}, hibernate}
  		| {stop, Reason :: normal | term(), NewStateData :: #statedata{}}.
  %% @doc Handle a received message.
  