+class pagetree(object):
+ """Base class for objects in the tree of pages and pagelists.
+
+ All pagetree objects should contain an attribute `stack', contains
+ a list of pairs. The last pair in the list should be the pagetree
+ object which yielded this pagetree object, along with the index
+ which yielded it. Every non-last pair should be the same
+ information for the pair following it. The only objects with empty
+ `stack' lists should be `manga' objects."""
+ pass
+
+class pagelist(pagetree):