first commit

vendor/league/flysystem/src/PortableVisibilityGuard.php

@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace League\Flysystem;
+
+final class PortableVisibilityGuard
+{
+    public static function guardAgainstInvalidInput(string $visibility): void
+    {
+        if ($visibility !== Visibility::PUBLIC && $visibility !== Visibility::PRIVATE) {
+            $className = Visibility::class;
+            throw InvalidVisibilityProvided::withVisibility(
+                $visibility,
+                "either {$className}::PUBLIC or {$className}::PRIVATE"
+            );
+        }
+    }
+}