Created new action to track visits, which returns an empty pixel

module/Core/src/Action/PixelAction.php

@@ -0,0 +1,15 @@
+<?php
+declare(strict_types=1);
+
+namespace Shlinkio\Shlink\Core\Action;
+
+use Psr\Http\Message\ResponseInterface;
+use Shlinkio\Shlink\Common\Response\PixelResponse;
+
+class PixelAction extends AbstractTrackingAction
+{
+    protected function createResp(string $longUrl): ResponseInterface
+    {
+        return new PixelResponse();
+    }
+}