code: def get_selected_series(self):
      if self.GetFocusedItem().ID is not None:
          idx = self.GetFocusedItem()
          parent = self.GetItemParent(idx)
          if not self.is_folder(parent):
              # This is a series within a file. Find the index.
              tgt = 0
              child_idx, cookie = self.GetFirstChild(parent)
              while child_idx.IsOk():
                  if child_idx == idx:
                      # This is the series we are looking at
                      return tgt
                  child_idx, cookie = self.GetNextChild(parent, cookie)
                  tgt += 1
      return None
  
imports: import logging
  import os
  import sys
  import uuid
  from urllib.request import url2pathname
  from urllib.parse import urlparse
  import wx
  import wx.lib.scrolledpanel
  from cellprofiler_core.pipeline import ImageFile
  from cellprofiler_core.preferences import report_progress
label_desc: Use image node_id 24 for calling the PathListCtrl obj's underlying member method code with example usage: obj.get_selected_series() and returns: None, tgt