From 8dd85104eff5c4e521162b03997b5dbeb7fc5501 Mon Sep 17 00:00:00 2001
From: "Vyacheslav N. Boyko" <mail4bvn@gmail.com>
Date: Tue, 9 Jan 2018 17:08:05 +0300
Subject: [PATCH] added prev method

---
 src/main/java/ru/bvn13/fsm/FSM.java | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/main/java/ru/bvn13/fsm/FSM.java b/src/main/java/ru/bvn13/fsm/FSM.java
index 964d28c..a220ddf 100644
--- a/src/main/java/ru/bvn13/fsm/FSM.java
+++ b/src/main/java/ru/bvn13/fsm/FSM.java
@@ -80,6 +80,17 @@ public class FSM {
         nextState(nextState);
     }
 
+    public void prev() throws FSMException {
+        if (done) {
+            return;
+        }
+        currentState.afterEvent();
+        if (getPreviousState() == null) {
+            return;
+        }
+        nextState(getPreviousState());
+    }
+
     private void nextState(State state) {
         state.beforeEvent();
         previousState = currentState;