Because the many-to-many relationships are not real relationships,
they can not be introspected with DBIx::Class. Many-to-many
relationships are actually just a collection of convenience methods
installed to bridge two relationships. This DBIx::Class component
can be used to store all relevant information about these
non-relationships so they can later be introspected and examined.

This module is fairly esoteric and, unless you are dynamically
creating something out of of a DBIC Schema, is probably the wrong
solution for whatever it is you are trying to do. Please be advised
that compatibility is not guaranteed for DBIx::Class 0.09000+. We
will try to mantain all compatibility, but internal changes might
make it impossible.

WWW: http://search.cpan.org/dist/DBIx-Class-IntrospectableM2M/