title: TypeError: AsyncConsumer.__call__() missing 1 required positional argument: 'send'
body: <p>consumers.py</p>
  <pre><code>import json
  from channels.generic.websocket import AsyncWebsocketConsumer
  
  class ChatRoomConsumer(AsyncWebsocketConsumer):
      async def connect(self):
          self.room_name= self.scope['url_route']['kwargs']['room_name']
          self_room_group_name='chat_%s' % self.room_name
          
          await self.channel_layer.group_add (
              self.room_group_name,
              self.channel_name
      )
  
          await self.accept()
  
          await self.channel_layer.group_send(
              self.room_group_name,
              {
                      'type':'tester_message',
                      'tester':'Hello world',
              }
          )
      async def tester_message(self,event):
          tester =event['tester']
          await self.send(text_data=json.dumps({
              'tester':tester,
  
      }))
      async def disconnect(self, code_close):
          await self.channel_layer.group_discard(
              self.room_group_name,
              self.channel_name
          )
  
      pass
  </code></pre>