resolveType arguments do not match documentation

[lukeify]

According to the documentation on interfaces for this repository, the resolveType method receives an argument $root, as so:

   public function resolveType($root)
    {
        // Use the resolveType to resolve the Type which is implemented trough this interface
        $type = $root['type'];
        if ($type === 'human') {
            return GraphQL::type('Human');
        } else if  ($type === 'droid') {
            return GraphQL::type('Droid');
        }
    }

This does not appear to be the case currently: