src/Theme/Theme.php
public function initiate()
    {
        $baseUrl = $this->app->make('request')->root();

        // Register relative and absolute URL for theme usage.
        $this->absoluteUrl = \rtrim($baseUrl, '/').'/themes';
        $this->relativeUrl = \trim(\str_replace($baseUrl, '/', $this->absoluteUrl), '/');

        return $this;
    }
public function initiate()
    {
        $baseUrl = $this->app->make('request')->root();

        // Register relative and absolute URL for theme usage.
        $this->absoluteUrl = \rtrim($baseUrl, '/').'/themes';
        $this->relativeUrl = \trim(\str_replace($baseUrl, '/', $this->absoluteUrl), '/');

        return $this;
    }
Start theme engine, this should be called from application booted
or whenever we need to overwrite current active theme per request.

@return $this