From 9044b30475630b2498b97f742943610ccef3ee1a Mon Sep 17 00:00:00 2001
From: Daniil Gentili <daniil@daniil.it>
Date: Tue, 1 Nov 2022 13:40:16 +0100
Subject: [PATCH] Fix

---
 src/Hooks/TestCaseHandler.php | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/Hooks/TestCaseHandler.php b/src/Hooks/TestCaseHandler.php
index 0ecf897..57a64b7 100644
--- a/src/Hooks/TestCaseHandler.php
+++ b/src/Hooks/TestCaseHandler.php
@@ -337,12 +337,12 @@ static function (
                     $provider_docblock_location
                 ): void {
                     if ($is_optional) {
-                        if (method_exists($param_type, 'setPossiblyUndefined')) {
-                            /** @var Union */
-                            $param_type = $param_type->setPossiblyUndefined(true);
-                        } else {
+                        if (VersionUtils::packageVersionIs('vimeo/psalm', '<', '5.0')) {
                             $param_type = clone $param_type;
                             $param_type->possibly_undefined = true;
+                        } else {
+                            /** @var Union */
+                            $param_type = $param_type->setPossiblyUndefined(true);
                         }
                     }
                     if ($codebase->isTypeContainedByType($potential_argument_type, $param_type)) {