code: def test_fixdoc(self):
      # Put here until better place for miscellaneous test.
      def func():
          "docstring"
  
      run.fixdoc(func, "more")
      self.assertEqual(func.__doc__, "docstring\n\nmore")
      func.__doc__ = None
      run.fixdoc(func, "more")
      self.assertEqual(func.__doc__, "more")
  
imports: from idlelib import run
  import io
  import sys
  from test.support import captured_output, captured_stderr
  import unittest
  from unittest import mock
  import idlelib
  from idlelib.idle_test.mock_idle import Func
label_desc: Use image node_id 4 for calling the RecursionLimitTest obj's underlying member method code with example usage: obj.test_fixdoc() without return types