Youshido\Tests\StarWars\Schema\DroidType::build PHP Method

    public function build($config)
    {
        parent::build($config);
        $config->getField('friends')->getConfig()->set('resolve', function ($droid) {
            return StarWarsData::getFriends($droid);
        });
        $config->addField('primaryFunction', TypeMap::TYPE_STRING);
    }