You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: hubot.rb
    path of file: ./repos/janky/lib/janky/chat_service
    
    the code of the file until where you have to start completion: module Janky
  module ChatService
    class Hubot
      def initialize(settings)
        @available_rooms = settings["JANKY_CHAT_HUBOT_ROOMS"]
        @default
    
      def initialize(settings)
        @available_rooms = settings["JANKY_CHAT_HUBOT_ROOMS"]
        @default_room = settings["JANKY_CHAT_HUBOT_DEFAULT_ROOM"]
        url = settings["JANKY_CHAT_HUBOT_URL"]
        if url.nil? || url.empty?
          raise Error, "JANKY_CHAT_HUBOT_URL setting is required"
        end