code: def unregister_maybe_terminate(self, edit):
      try:
          key = self.inversedict[edit]
      except KeyError:
          print("Don't know this EditorWindow object.  (close)")
          return
      if key:
          del self.dict[key]
      del self.inversedict[edit]
      if not self.inversedict:
          self.root.quit()
  
file_path: cpython/Lib/idlelib/filelist.py
imports: import os
  from tkinter import messagebox
label_desc: Use image node_id 6 for calling the FileList obj's underlying member method code with example usage: obj.unregister_maybe_terminate(edit) without return types