diff --git a/README.md b/README.md
index e18f544..5070925 100644
--- a/README.md
+++ b/README.md
@@ -83,12 +83,21 @@ class m150722_150100_multiple_tree extends Migration
 ```php
 use paulzi\nestedsets\NestedSetsBehavior;
 
+/**
+ * @property integer $id
+ * @property integer $lft
+ * @property integer $rgt
+ * @property integer $depth
+ *
+ * @mixin NestedSetsBehavior
+ */
+
 class Sample extends \yii\db\ActiveRecord
 {
     public function behaviors() {
         return [
             [
-                'class' => NestedSetsBehavior::className(),
+                'class' => NestedSetsBehavior::class,
                 // 'treeAttribute' => 'tree',
             ],
         ];
@@ -291,4 +300,4 @@ To delete a node with descendants:
 $node11 = Sample::findOne(['name' => 'node 1.1']);
 $node11->delete(); // delete node, children come up to the parent
 $node11->deleteWithChildren(); // delete node and all descendants 
-```
\ No newline at end of file
+```