=head1 CANDIDATE OBJECTS

=head2 link

a link is the full set of information about a link to another infostructure.

we have to be able to store and recover links so that we can later
give out information about them.

links contain URLs, result histories etc.

=head2 tester

a tester knows how to find out if a link is broken or not

=head2 link_updater

B<not implemented>

knows how to take the results of a tester and apply them to a link...

=head2 result

B<not implemented>

a result could be what we get when we run a tester

=head2 reporter

a reporter knows how to generate a report about the status of links

=head2 selector

knows how to filter links.

=cut

=head1 THOUGHTS

do not multiply entities beyond necessity

we need a tester to bundle together testing stuff

we need a link to remember about link information

we need output through reporters

it would be nice to have testers that work on urls only, using
options.. this would allow us to share code with people who want to do
instant testing.

=cut
