code: def extend(mod)
           raise TypeError, '`mod` should be a module' unless mod.class == Module
           unless is_a?(mod)
             mod.extend ::Plezi::Controller::ClassMethods
             super(mod)
           end
           _pl_ws_map.update mod._pl_ws_map
           _pl_ad_map.update mod._pl_ad_map
        end
docs: Experimental: takes a module to be used for Websocket callbacks events.
  
   This function can only be called **after** a websocket connection was established (i.e., within the `on_open` callback).
  
   This allows a module "library" to be used similar to the way "rooms" are used in node.js, so that a number of different Controllers can listen to shared events.
  
   By dynamically extending a Controller instance using a module, Auto Dispatch events can be routed to the newly available methods.
  
   Notice: It is impossible to `unextend` an extended module at this time.