The Perl 5 module MooseX::Singleton lets you easily upgrade your
Moose class to a singleton.  All you should need to do to transform
your class is to change 'use Moose' to 'use MooseX::Singleton'.
MooseX::Singleton gives your class an 'instance' method that can
be used to get a handle on the singleton.

Homepage:
https://metacpan.org/release/MooseX-Singleton
