I have the xy interface in file interfaces.php:

    interface xy
    {
       public function create(x,y);
    }

and class abc in file abc.php:

    require_once 'interfaces.php';

    class abc implements xy
    {
      public class()
      {
        ...
      }
    }

PHP editor does not report any problem with it (note: my class does not have x and y input variables), but when I want to load that class (require_once of abc.php in some PHP file) during execution PHP/Netbeans stops there without any error report or hint!