feat: initial version

Signed-off-by: Sebastian Krupinski <root@LAPTOP-7DVOR6NC>

lib/Client/Mime/Part/MultiPart.php

@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Gricob\IMAP\Mime\Part;
+
+final readonly class MultiPart extends Part
+{
+    /**
+     * @param array<string,string> $attributes
+     * @param list<Part> $parts
+     */
+    public function __construct(
+        string $subtype,
+        array $attributes,
+        public array $parts,
+    ) {
+        parent::__construct('multipart', $subtype, $attributes);
+    }
+
+    public function findPartByMimeType(string $mimeType): ?SinglePart
+    {
+        foreach ($this->parts as $part) {
+            if ($matchedPart = $part->findPartByMimeType(strtolower($mimeType))) {
+                return $matchedPart;
+            }
+        }
+
+        return null;
+    }
+}