Comment added on Transition.Execute()
@@ -45,6 +45,8 @@ type Transition interface {
// The result is asynchronously notified by cb. canceler can be used
// to cancel it after calling Execute. After canceler returns true,
// all succeeding cb functions may not be called back.
+ // REMARK: It is assumed to be called once. Any additional call returns
+ // error.
Execute(cb TransitionCallback) (canceler func() bool, err error)
// Result returns service manager defined result bytes.
