module ActiveAdmin::Settings::Inheritance::ClassMethods

def deprecated_inheritable_setting(name, default)
  deprecated_setting name, default
  @setting_heirs.each{ |c| c.deprecated_setting name, default }
end

def inheritable_setting(name, default)
  setting name, default
  @setting_heirs.each{ |c| c.setting name, default }
end

def settings_inherited_by(heir)
  (@setting_heirs ||= []) << heir
  heir.send :include, ActiveAdmin::Settings
end