code: def make_levels_set(levels):
      '''make set efficient will convert all lists of items
      in levels to a set to speed up operations'''
      for level_key,level_filters in levels.items():
          levels[level_key] = make_level_set(level_filters)
      return levelf make_levels_set(levels):
      '''make set efficient will convert all lists of items
      in levels to a set to speed up operations'''
      for level_key,level_filters in levels.items():
          levels[level_key] = make_level_set(level_filters)
      return levels
docs: make set efficient will convert all lists of items
      in levels to a set to speed up operations