detach_from

# File activesupport/lib/active_support/subscriber.rb, line 50
      def detach_from(namespace, notifier = ActiveSupport::Notifications)
        @namespace  = namespace
        @subscriber = find_attached_subscriber
        @notifier   = notifier

        return unless subscriber

        subscribers.delete(subscriber)

        # Remove event subscribers of all existing methods on the class.
        fetch_public_methods(subscriber, true).each do |event|
          remove_event_subscriber(event)
        end

        # Reset notifier so that event subscribers will not add for new methods added to the class.
        @notifier = nil
      end