This is Perl module Object::Container.
INSTALLATION
Object::Container installation is straightforward. If your CPAN shell is set up,
you should just be able to do
    % cpan Object::Container
Download it, unpack it, then build it as per the usual:
    % perl Makefile.PL
    % make && make test
Then install it:
    % make install
DOCUMENTATION
Object::Container documentation is available as in POD. So you can do:
    % perldoc Object::Container
to read the documentation online with your favorite pager.
Daisuke Murase