class_docstr: Tests for Debugger that do not need a real root.
code: def test_ret(self):
      with patch.object(self.debugger, "frame") as frame:
          self.debugger.ret()
          self.idb.set_return.assert_called_once_with(frame)
  
imports: from idlelib import debugger
  from collections import namedtuple
  from textwrap import dedent
  from tkinter import Tk
  from test.support import requires
  import unittest
  from unittest import mock
  from unittest.mock import Mock, patch
label_desc: Use image node_id 6 for calling the DebuggerTest obj's underlying member method code with example usage: obj.test_ret() without return types