so $class will have name of the class
and $type will have type of class
suppose I have class A, clas B,...
if I want to have new class a of type A
should I get by get_new(a,A);
is that correct ?
Not quite. It's designed to be a class method, so you would call it like: Factory->get_new("A") which implicitly sends "Factory" as the first argument to the method.