def include_events(container)
      handlers = container.instance_variable_get '@event_handlers'
      return unless handlers

      @event_handlers ||= {}
      @event_handlers.merge!(handlers) { |_, old, new| old + new }
    end
def include_events(container)
      handlers = container.instance_variable_get '@event_handlers'
      return unless handlers

      @event_handlers ||= {}
      @event_handlers.merge!(handlers) { |_, old, new| old + new }
    end
Adds all event handlers from another container into this one. Existing event handlers will be overwritten.
 @param container [Module] A module that `extend`s {EventContainer} from which the handlers will be added.