Fix return type

Author: trowski

examples/dns.php

@@ -16,7 +16,7 @@
 
 while ($nameserver === "" && ($key = array_shift($keys))) {
     try {
-        $nameserver = WindowsRegistry::read($key) ?? '';
+        $nameserver = WindowsRegistry::read($key);
     } catch (KeyNotFoundException $e) {
     }
 }
@@ -27,7 +27,7 @@
     foreach ($subKeys as $key) {
         foreach (["NameServer", "DhcpNameServer"] as $property) {
             try {
-                $nameserver = WindowsRegistry::read("{$key}\\{$property}") ?? '';
+                $nameserver = WindowsRegistry::read("{$key}\\{$property}");
 
                 if ($nameserver !== "") {
                     break 2;

src/WindowsRegistry.php

@@ -17,7 +17,7 @@ private function __construct()
         // forbid instances
     }
 
-    public static function read(string $key): ?string
+    public static function read(string $key): string
     {
         $key = \str_replace('/', "\\", $key);
         $parts = \explode("\\", $key);