[csm] nullable setter fixture

tests/Util/ClassSourceManipulatorTest.php

@@ -176,7 +176,7 @@ public function getAddSetterTests(): \Generator
             null,
             false,
             [],
-            'User_simple.php',
+            'User_simple_null_type.php',
         ];
     }
 

tests/Util/fixtures/add_setter/User_simple_null_type.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace App\Entity;
+
+use Doctrine\ORM\Mapping as ORM;
+
+#[ORM\Entity]
+class User
+{
+    #[ORM\Id]
+    #[ORM\GeneratedValue]
+    #[ORM\Column()]
+    private ?int $id = null;
+
+    public function getId(): ?int
+    {
+        return $this->id;
+    }
+
+    public function setFooProp($fooProp): self
+    {
+        $this->fooProp = $fooProp;
+
+        return $this;
+    }
+}