add state nodes for regex state machine

StgSharp.Common/State/ISimpleStateMachine.cs

@@ -2,8 +2,8 @@
 // -----------------------------------------------------------------------
 // file="ISimpleStateMachine"
 // Project: StgSharp
-// AuthorGroup: Nitload Space
-// Copyright (c) Nitload Space. All rights reserved.
+// AuthorGroup: Nitload
+// Copyright (c) Nitload. All rights reserved.
 //     
 // Permission is hereby granted, free of charge, to any person obtaining a copy
 // of this software and associated documentation files (the "Software"), to deal
@@ -35,13 +35,13 @@ using System.Threading.Tasks;
 namespace StgSharp.State
 {
     public interface ISimpleStateMachine<TStateNode, TStateLabel, TStateContext>
-        where TStateNode : ISimpleStateMachineNode<TStateLabel, TStateContext>
+        where TStateNode : SimpleStateMachineNode<TStateNode, TStateLabel, TStateContext>
         where TStateLabel : unmanaged, IEquatable<TStateLabel>
         where TStateContext : StateContext
     {
 
-        ref readonly TStateNode this[
-                                TStateLabel label
+        TStateNode this[
+                   TStateLabel label
         ] { get; }
 
         ref readonly TStateNode GetCurrentStateNode();