code: def __init__(self):
      self.length = 0
      # Dictionary to hold combination of words that can be formed,
      # from any given word. By changing one letter at a time.
      self.all_combo_dict = defaultdict(list)
  
imports: from collections import defaultdict
label_desc: Use image node_id 1 to create a new Solution object from inherited base classes: object with example: obj = Solution()