Right now that won't change anything, but it'll prevent problems when $app will
be an instance.
# Future - isa => 'ClassName|Catalyst' performance?
# required => 1 breaks tests..
-has _application => (is => 'ro');
+has _application => (is => 'ro', weak_ref => 1);
sub _app { (shift)->_application(@_) }
override BUILDARGS => sub {