TIECLASS Name: POP::List Desc: Implements a tied array which contains a list of persistent objects, lazily, so that it at first just contains the objects' pids, but goes out and restores the object when it is accessed.

METHOD Name: POP::List::TIEARRAY Desc: The tied array constructor; takes the name of this collection in our parent, the parent and a list of initial values

METHOD Name: POP::List::FETCH Desc: Called whenever an element of the tied array is accessed, this will restore the object if it hasn't already been, and then return it.

METHOD Name: POP::List::STORE Desc: Called whenever an element in the array is set; tells our parent to update persistence.

METHOD Name: POP::List::FETCHSIZE Desc: Called whenever the length of the array is requested.

METHOD Name: POP::List::STORESIZE Desc: Called whenever the length of the array is set.