code: def powerset(iterable):
      """Yields all possible subsets of the iterable.
  
          >>> list(powerset([1, 2, 3]))
          [(), (1,), (2,), (3,), (1, 2), (1, 3), (2, 3), (1, 2, 3)]
  
      :func:`powerset` will operate on iterables that aren't :class:`set`
      instances, so repeated elements in the input will produce repeated elements
      in the output. Use :func:`unique_everseen` on the input to avoid generating
      duplicates:
  
          >>> seq = [1, 1, 0]
          >>> list(powerset(seq))
          [(), (1,), (1,), (0,), (1, 1), (1, 0), (1, 0), (1, 1, 0)]
          >>> from more_itertools import unique_everseen
          >>> list(powerset(unique_everseen(seq)))
          [(), (1,), (0,), (1, 0)]
  
      """
      s = list(iterable)
      return chain.from_iterable(
          combinations(s, r) for r in range(len(s) + 1)
      )
  
imports: import math
  import operator
  from collections import deque
  from collections.abc import Sized
  from functools import partial, reduce
  from itertools import chain, combinations, compress, count, cycle, groupby, islice, product, repeat, starmap, tee, zip_longest
  from random import randrange, sample, choice
label_desc: Use image node_id 19 for calling a global function with example usage: powerset(iterable) and returns: chain