code: def error_event(self, ev, key=None):
      raise RuntimeError("Errored")
  
imports: import unittest
  import copy
  from vispy.util.event import Event, EventEmitter, EmitterGroup
  from vispy.util import use_log_level
  from vispy.testing import run_tests_if_main, assert_true, assert_raises
label_desc: Use image node_id 10 for calling the TestGroups obj's underlying member method code with example usage: obj.error_event(ev, key) without return types