munge your "has" (works with Moo, Moose and Mouse)

 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.