Bug Report

The IssetOnPropertyObjectToPropertyExistsRector changes code while it shouldn't.

Minimal PHP Code Causing Issue

https://getrector.com/demo/fc241ad4-ac82-4120-bfe7-27ffc62ac965

-        if (! isset($values['_identity']->value)) {
+        if ($values['_identity']->value === null) {

Expected Behaviour

Rector should leave this code snippet, or allow for the array key to not exist, like:

-        if (! isset($values['_identity']->value)) {
+        if ($values['_identity']?->value === null) {