docstr: Emit Event class with pre-specified type
docstr_tok: ["Emit","Event","class","with","pre-specified","type"]
code: def test_typed_event(self):
      """Emit Event class with pre-specified type"""
      em = EventEmitter(event_class=TypedEvent)
      ev = self.try_emitter(em)  # no need to specify type here
      self.assert_result(
          event=ev,
          event_class=TypedEvent,
          source=None,
          type="typed_event",
          sources=[None],
      )
  
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 8 for calling the TestEmitters obj's underlying member method code with example usage: obj.test_typed_event() without return types