$page = A:B:C->new();

##</code><code>##

  $page = A:B:C:D1->new();
  $page = A:B:C:D2->new();

##</code><code>##

  $page = A:B:C->new();
  $page->check_if_i_should_be_a_subclass_instead();
  $page->render(); # render method from A:B:C or A:B:C:D1  based on above method result