new_contents: #!/usr/bin/env python
  import pytest
  
  import pg_bawler.core
  
  
  @pytest.mark.asyncio
  async def test_simple_listen():
  
      class NotificationListener(
          pg_bawler.core.BawlerBase,
          pg_bawler.core.ListenerMixin
      ):
          pass
  
      class NotificationSender(
          pg_bawler.core.BawlerBase,
          pg_bawler.core.SenderMixin
      ):
          pass
  
      connection_params = dict(
          dbname='pg_bawler_test',
          user='pg_bawler_test',
          host='postgres',
          password='postgres')
  
      nl = NotificationListener(connection_params=connection_params)
      ns = NotificationSender(connection_params=connection_params)
  
      payload = 'aaa'
      channel_name = 'pg_bawler_test'
  
      await nl.register_channel(channel='pg_bawler_test')
      await ns.send(channel=channel_name, payload=payload)
      notification = await nl.get_notification()
      assert notification.channel == channel_name
      assert notification.payload == payload
  
subject: Add initial test for listener module