code: def testEmitOrder(self):
      handlersData = []
  
      def handler3():
          handlersData.append(3)
  
      def handler1():
          handlersData.append(1)
  
      def handler2():
          handlersData.append(2)
  
      event = observer.Event()
      event.subscribe(handler1)
      event.subscribe(handler2)
      event.subscribe(handler3)
      event.emit()
      self.assertTrue(handlersData == [1, 2, 3])
  
      handlersData = []
      event = observer.Event()
      event.subscribe(handler3)
      event.subscribe(handler2)
      event.subscribe(handler1)
      event.emit()
      self.assertTrue(handlersData == [3, 2, 1])
  
imports: import datetime
  import copy
  from six.moves import xrange
  from .None import common
  from pyalgotrade import observer
  from pyalgotrade import dispatcher
label_desc: Use image node_id 1 for calling the EventTestCase obj's underlying member method code with example usage: obj.testEmitOrder() without return types