vague first draft of v3. TenantModelTest is passing

src/Events/Contracts/DomainEvent.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace Stancl\Tenancy\Events\Contracts;
+
+use Illuminate\Queue\SerializesModels;
+use Stancl\Tenancy\Database\Models\Domain;
+
+abstract class DomainEvent
+{
+    use SerializesModels;
+
+    /** @var Domain */
+    public $domain;
+
+    public function __construct(Domain $domain)
+    {
+        $this->domain = $domain;
+    }
+}