laravel 5 Class implements Iterator

I am trying to integrate an existing library into Laravel5 which itself is not namespaced and uses its own classes in subfolders using require. I have placed it at 'app/API/libname/mainlibclass.php'. with sibling directory at 'app/API/libname/toolkit' which contains the classes the library uses.

Calling from a Laravel controller I am unable to create the class using a require statement (correct?) before

$objectinstance=new Mainlibclass();

so in the main Laravel app I have

use app/API/libname/Mainlibclass

then later the usual

$objectinstance=new Mainlibclass();

In the existing library and each of its own used classes I set

namespace app/API/libname

and 'use' where needed. I now have no class not found but one of the files uses 'implements Iterator' - I am getting error Interface 'App\API\libname\Iterator' not found.

via Chebli Mohamed