State pattern is maintainable

state pattern change readme.rst

Behavioral/State/ContextOrder.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace DesignPatterns\Behavioral\State;
+
+class ContextOrder extends StateOrder
+{
+    public function getState():StateOrder
+    {
+        return static::$state;
+    }
+
+    public function setState(StateOrder $state)
+    {
+        static::$state = $state;
+    }
+
+    public function done()
+    {
+        static::$state->done();
+    }
+
+    public function getStatus(): string
+    {
+        return static::$state->getStatus();
+    }
+}