create new instance from class names

Feed.php

<?php

class Feed {
    public function items()
    {
        return $this->feedItems()->map(function($element) {
            return $this->createInstance($element['content_type'], $element);
        });
    }

    private function createInstance($content_type, $attributes)
    {
        $class_name            = preg_replace('/\s+/', '', $content_type);
        $namespaced_class_name = "\\App\\Models\\{$class_name}";
        if (!class_exists($namespaced_class_name)) {
            throw new \Exception("Class '{$namespaced_class_name}' not found");
        }
        return new $namespaced_class_name($attributes);
    }
}