anchor.diff:  		From :: {Pid, Tag},
   		Pid :: pid(),
   		Tag :: term(),
  -		StateData :: term(),
  +		StateData :: statedata(),
   		Result :: {reply, Reply, NextStateName, NewStateData}
   				| {reply, Reply,NextStateName, NewStateData, Timeout}
   				| {reply, Reply,NextStateName, NewStateData, hibernate}
  
positive.code: 				| {stop, Reason, Reply, NewStateData} | {stop, Reason, NewStateData},
  				Reply :: term(),
  		NextStateName :: atom(),
  		NewStateData :: term(),
  		Timeout :: pos_integer() | infinity,
  		Reason :: normal | term().
  %% @doc Handle events sent with {@link //stdlib/gen_fsm:sync_send_event/2.
  
negative.code: 				| {stop, Reason, Reply, NewStateData} | {stop, Reason, NewStateData},
  				Reply :: term(),
  		NextStateName :: atom(),
  		NewStateData :: statedata(),
  		Timeout :: pos_integer() | infinity,
  		Reason :: normal | term().
  %% @doc Handle events sent with {@link //stdlib/gen_fsm:sync_send_event/2.
  