MooseX::MungeHas alters the behaviour of the attributes of your Moo, Moose or
Mouse based class.

It manages to support all three because it doesn't attempt to do anything smart
with metathingies; it simply installs a wrapper for has that munges the
attribute specification hash before passing it on to the original has function.

WWW: https://metacpan.org/pod/MooseX::MungeHas