Factory.php

<?php
interface Thing
{
    public function whatever();
}

class ThingFactory
{
    private $things;
  
    /**
     * @param \Thing[] $things name => instance link
     */
    public function __construct($things)
    {
        $this->things = $things;
    }

    public function make(string $kind): Thing
    {
        if (!isset($this->things[$kind])) {
            throw new \InvalidArgumentException('...');
        }
              
        return $this->things[$kind];
    }
}