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: room.rb
    path of file: ./repos/lita/lib/lita
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require "redis-namespace"

require_relative "util"

module Lita
  # A room in the chat service. Persisted in Redis.
  # @since 4.4.0
  class Room
    class << self
      # Create
    
      def create_or_update(id, metadata = {})
        existing_room = find_by_id(id)
        metadata = Util.stringify_keys(metadata)
        metadata = existing_room.metadata.merge(metadata) if existing_room
        room = new(id, metadata)
        room.save
        room
      end