Helpers and Other Conventions

Without getting hungup on specific names, etc, it sounds like something along the lines of the following might be a good approach. Thoughts?

CodeIgniter4?? ...

system/helpers/URL.php

Code:

namespace CodeIgniter\Helpers\URL;

    function siteURL($uri = '', $protocol = NULL)
    {
        return ...
    }
...

application/whatever...

Code:

use CodeIgniter\Helpers\URL;
...
echo URL\siteURL();

I borrow...

Code:

use CodeIgniter\Helpers\URL;

function site_url()
{
   return URL\SiteURL();
}

echo site_url();

and done...