docstr: Event.blocked
docstr_tok: ["Event.blocked"]
code: def test_event_block(self):
      """Event.blocked"""
      em = EventEmitter(type="test_event")
  
      def cb1(ev):
          ev.handled = True
          self.result = 1
  
      def cb2(ev):
          ev.blocked = True
          self.result = 2
  
      em.connect(self.record_event)
      em.connect(cb1)
      self.result = None
      em()
      self.assert_result()
  
      em.connect(cb2)
      self.result = None
      em()
      assert self.result == 2
  
imports: import unittest
  import copy
  import functools
  from vispy.util.event import Event, EventEmitter
  from vispy.testing import run_tests_if_main, assert_raises, assert_equal
label_desc: Use image node_id 21 for calling the TestEmitters obj's underlying member method code with example usage: obj.test_event_block() without return types