code: def test_dispatch_error(self):
      self.func.__init__(TclError())
      self.assertEqual(self.redir.dispatch("insert", False), "")
      self.assertEqual(self.redir.dispatch("invalid"), "")
  
imports: from test.test_support import requires
  import unittest
  from idlelib.idle_test.mock_idle import Func
  from Tkinter import Tk, Text, TclError
  from idlelib.WidgetRedirector import WidgetRedirector
label_desc: Use image node_id 12 for calling the WidgetRedirectorTest obj's underlying member method code with example usage: obj.test_dispatch_error() without return types