<?php
if (isset($runtime)) {
    return new class {
        public $bar;
        public function bing($foo = null) {
            if ($foo) $foo->bing();
        }
    };
}

$runtime = 1;
$oldFoo = require(__FILE__);
$newFoo = require(__FILE__);

var_dump(get_class_methods($oldFoo));
var_dump(get_object_vars($oldFoo));

$newFoo->bing($oldFoo);
?>