code: def test_DirBrowserTreeItem(self):
      # Issue16226 - make sure that getting a sublist works
      d = pathbrowser.DirBrowserTreeItem("")
      d.GetSubList()
      self.assertEqual("", d.GetText())
  
      dir = os.path.split(os.path.abspath(idlelib.__file__))[0]
      self.assertEqual(d.ispackagedir(dir), True)
      self.assertEqual(d.ispackagedir(dir + "/Icons"), False)
  
imports: from idlelib import pathbrowser
  import unittest
  from test.support import requires
  from tkinter import Tk
  import os.path
  import pyclbr
  import sys
  from idlelib.idle_test.mock_idle import Func
  import idlelib
  from idlelib import browser
  from idlelib.tree import TreeNode
label_desc: Use image node_id 1 for calling the DirBrowserTreeItemTest obj's underlying member method code with example usage: obj.test_DirBrowserTreeItem() without return types