Add messagebox, bugfixes

src/Tree/ObjectNode.php

@@ -15,6 +15,15 @@ class ObjectNode extends Node implements CollapsibleNode
         $this->properties[$key] = $value;
     }
 
+    public function rename(string $key, string $newKey)
+    {
+        $renamed = [];
+        foreach ($this->properties as $k=>$v) {
+            $renamed[($k==$key)?$newKey:$k] = $v;
+        }
+        $this->properties = $renamed;
+    }
+
     public function unset(string $key)
     {
         unset($this->properties[$key]);