rails chatルーム　channelのspeakメソッド　ActionCable.server.broadcast 'room

rails でchatアプリを作るための練習をしています。channelのspeakメソッドでdbに保存して送るところで、
Could not execute command from ({"command"=>"message", "identifier"=>"{"channel":"RoomChannel"}", "data"=>"{"message":"aaaaaaaa","action":"speak"}"}) [NameError - uninitialized constant RoomChannel::Messsage]
と出てしまいます。(成功したらアラートが表示されるはずです
コード
。）
NameErrorとありますが、手本を見ながらしていて、手本と同じように入力しているはずで、どのように直したらいいのか、また違うことが原因なのか分かりません。どなたか、ご教授ください。お願いします。

ruby
1class RoomChannel < ApplicationCable::Channel
2  def subscribed
3    
4  end
5
6  def unsubscribed
7    # Any cleanup needed when channel is unsubscribed
8  end
9
10  def speak(data)
11    Messsage.create!(content: data['message'])
12    ActionCable.server.broadcast 'room_channel' ,data['message']
13  end
14end
15

ruby
1App.room = App.cable.subscriptions.create("RoomChannel", {
2  connected: function() {
3    console.log('connectedddd')
4  },
5
6  disconnected: function() {
7    // Called when the subscription has been terminated by the server
8  },
9
10  received: function(data) {
11    alert(data)
12  },
13
14  speak: function() {
15    return this.perform('speak',{message:"aaaaaaaa"});
16  }
17});
18

log
1Started GET "/cable" for ::1 at 2020-01-29 20:15:26 +0900
2Started GET "/cable/" [WebSocket] for ::1 at 2020-01-29 20:15:26 +0900
3Successfully upgraded to WebSocket (REQUEST_METHOD: GET, HTTP_CONNECTION: Upgrade, HTTP_UPGRADE: websocket)
4Started GET "/cable" for 127.0.0.1 at 2020-01-29 20:15:27 +0900
5Started GET "/cable/" [WebSocket] for 127.0.0.1 at 2020-01-29 20:15:27 +0900
6Successfully upgraded to WebSocket (REQUEST_METHOD: GET, HTTP_CONNECTION: Upgrade, HTTP_UPGRADE: websocket)
7RoomChannel is transmitting the subscription confirmation
8RoomChannel is transmitting the subscription confirmation
9RoomChannel#speak({"message"=>"aaaaaaaa"})
10Could not execute command from ({"command"=>"message", "identifier"=>"{\"channel\":\"RoomChannel\"}", "data"=>"{\"message\":\"aaaaaaaa\",\"action\":\"speak\"}"}) [NameError - uninitialized constant RoomChannel::Messsage]: C:/Users/LS150/Desktop/chat_app2/app/channels/room_channel.rb:11:in `speak' | C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/actioncable-5.2.4.1/lib/action_cable/channel/base.rb:266:in `public_send' | C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/actioncable-5.2.4.1/lib/action_cable/channel/base.rb:266:in `dispatch_action' | C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/actioncable-5.2.4.1/lib/action_cable/channel/base.rb:168:in `block in perform_action' | C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/activesupport-5.2.4.1/lib/active_support/notifications.rb:170:in `instrument'
11