From f08fff6f54ffabb4c259a18f1cf00683e1fa97ba Mon Sep 17 00:00:00 2001
From: Andrea Marco Sartori <andrea.marco.sartori@gmail.com>
Date: Sun, 6 Nov 2022 01:06:49 +1000
Subject: [PATCH] Handle unset keys

---
 src/Tree.php | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/Tree.php b/src/Tree.php
index 9cfc334..b2e9c5d 100644
--- a/src/Tree.php
+++ b/src/Tree.php
@@ -90,7 +90,9 @@ class Tree implements IteratorAggregate
      */
     public function inObject(): bool
     {
-        return is_string($this->original[$this->depth]);
+        $key = $this->original[$this->depth] ?? null;
+
+        return is_string($key);
     }
 
     /**