# this is for an extra attribute constructor
# option, which is to be able to create a
# way for the class to access the history
-AttributesWithHistory->meta->add_attribute('history_accessor' => (
+AttributesWithHistory->meta->add_attribute('$!history_accessor' => (
reader => 'history_accessor',
init_arg => 'history_accessor',
predicate => 'has_history_accessor',
# this is a place to store the actual
# history of the attribute
-AttributesWithHistory->meta->add_attribute('_history' => (
+AttributesWithHistory->meta->add_attribute('$!_history' => (
accessor => '_history',
default => sub { {} },
));