Refactor more old code and get tests to pass

src/Listeners/QueueableListener.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace Stancl\Tenancy\Listeners;
+
+use Illuminate\Contracts\Queue\ShouldQueue;
+
+/**
+ * @method handle(object $event)
+ */
+abstract class QueueableListener implements ShouldQueue
+{
+    public static $shouldQueue = false;
+
+    public function shouldQueue($event)
+    {
+        if (static::$shouldQueue) {
+            return true;
+        } else {
+            // The listener is not queued so we manually
+            // pass the event to the handle() method.
+            $this->handle($event);
+
+            return false;
+        }
+    }
+}