code: def OnDoubleClick(self):
      if os.path.normcase(self.file[-3:]) != ".py":
          return
      if not os.path.exists(self.file):
          return
      PyShell.flist.open(self.file)
  
imports: import os
  import sys
  import pyclbr
  from idlelib import PyShell
  from idlelib.WindowList import ListedToplevel
  from idlelib.TreeWidget import TreeNode, TreeItem, ScrolledCanvas
  from idlelib.configHandler import idleConf
label_desc: Use image node_id 5 for calling the ModuleBrowserTreeItem obj's underlying member method code with example usage: obj.OnDoubleClick() without return types