code: def test_pusher(self):
      thread = WebSocketClientThread()
      thread.start()
      thread.join(30)
      # After 30 seconds the thread should have finished.
      if thread.isAlive():
          thread.stop()
          self.assertTrue(False)
  
imports: import unittest
  import threading
  import datetime
  from pyalgotrade.websocket import pusher
  from pyalgotrade.websocket import client
label_desc: Use image node_id 1 for calling the TestCase obj's underlying member method code with example usage: obj.test_pusher() without return types