Extract write related methods from ValueContainer

src/ValueContainer/ValueContainer.php

@@ -11,7 +11,7 @@
 /**
  * @package ActiveCollab\ValueContainer
  */
-class ValueContainer implements ValueContainerInterface
+class ValueContainer implements ValueContainerInterface, WriteableValueContainerInterface
 {
     /**
      * @var bool

src/ValueContainer/ValueContainerInterface.php

@@ -22,15 +22,4 @@ public function hasValue();
      * @return mixed
      */
     public function getValue();
-
-    /**
-     * @param  mixed $value
-     * @return $this
-     */
-    public function &setValue($value);
-
-    /**
-     * @return $this
-     */
-    public function &removeValue();
 }

src/ValueContainer/WriteableValueContainerInterface.php

@@ -0,0 +1,26 @@
+<?php
+
+/*
+ * This file is part of the Active Collab Utils project.
+ *
+ * (c) A51 doo <info@activecollab.com>. All rights reserved.
+ */
+
+namespace ActiveCollab\ValueContainer;
+
+/**
+ * @package ActiveCollab\ValueContainer
+ */
+interface WriteableValueContainerInterface
+{
+    /**
+     * @param  mixed $value
+     * @return $this
+     */
+    public function &setValue($value);
+
+    /**
+     * @return $this
+     */
+    public function &removeValue();
+}