code: def get_thumbnail_paths(self):
          
          thumbnail_path_tuples = []
          # channel thumbnail
          channel_info = self.get_channel_info()
          chthumbnail_path = channel_info.get('thumbnail_chan_path', None)
          if chthumbnail_path:
              chthumbnail_path_tuple = path_to_tuple(chthumbnail_path, windows=self.winpaths)
              thumbnail_path_tuples.append(chthumbnail_path_tuple)
          # content thumbnails
          for content_file_path_tuple, row in self.contentcache.items():
              thumbnail_path = row.get('thumbnail_chan_path', None)
              if thumbnail_path:
                  thumbnail_path_tuple = path_to_tuple(thumbnail_path, windows=self.winpaths)
                  thumbnail_path_tuples.append(thumbnail_path_tuple)
          return thumbnail_path_tuples
docs: Helper function used to avoid processing thumbnail files during `os.walk`.