code: def test_init(self):
      pb = self.pb
      eq = self.assertEqual
      eq(pb.master, self.root)
      eq(pyclbr._modules, {})
      self.assertIsInstance(pb.node, TreeNode)
      self.assertIsNotNone(browser.file_open)
  
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 3 for calling the PathBrowserTest obj's underlying member method code with example usage: obj.test_init() without return types