How to connect your php class to Phalcon?

Question

Phalcon

I do it like here:
https://docs.phalconphp.com/ru/latest/api/Phalcon_...
Added to loader.php:

$loader->registerNamespaces(
    array(
        'Inc\Libs' => 'inc/classes/'
    )
)->register();

In one of the controllers:
$obj = Inc\Libs\Some();
Not working:

Fatal error: Call to undefined function Inc\Libs\Some()