The Perl 5 module Mixin::ExtraFields provides a simple way to add
an arbitrary number of stashes for named data. These data can be
stored in the object, in a database, or anywhere else. The storage
mechanism is abstracted away from the provided interface, so one
storage mechanism can be easily swapped for another. Multiple
ExtraFields stashes can be mixed into one class, using one or many
storage mechanisms.

Homepage:
https://metacpan.org/release/Mixin-ExtraFields
