PHPstan analysis.

src/Ntfy/Ntfy.php

@@ -3,19 +3,18 @@ namespace App\Ntfy;
 
 class Ntfy
 {
-    protected $domain;
-    function __construct($domain)
+    protected string $domain;
+    function __construct(string $domain)
     {
         $this->domain = $domain;
     }
 
-    function send($topic,$title, $message)
+    function send(string $topic, string $title, string $message): void
     {
         file_get_contents(
             'https://'.$this->domain.'/'.$topic, false, stream_context_create(
                 ['http' => [
                 'method' => 'POST', 
-                'header' => 'Content-Type: text/plain',
                 'header' =>
                     "Content-Type: text/plain\r\n" .
                     "Title: $title\r\n",