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: base_channel.rb
    path of file: ./repos/activeadmin-chat/app/channels/active_admin/chat
    
    the code of the file until where you have to start completion: module ActiveAdmin
  module Chat
    class BaseChannel < ApplicationCable::Channel
      def subscribed
        conversation ? stream_for(conversation) : reject
      end

      def speak(data)
        message = 
    
      def speak(data)
        message = conversation.public_send(
          ActiveAdmin::Chat.message_relation_name.pluralize
        ).create!(
          sender: current_user,
          content: data['message']
        )

        message = ActiveAdmin::Chat::MessagePresenter.new(message)
        ActiveAdmin::Chat::AdminChannel.broadcast_to(conversation, message)
        ActiveAdmin::Chat::UserChannel.broadcast_to(conversation, message)
      end