code: def powerset(iterable):
      items_powers = [(item, 1 << i) for i, item in enumerate(iterable)]
      for i in range(1 << len(items_powers)):
          for item, power in items_powers:
              if i & power:
                  yield item
  
file_path: python-igraph/tests/test_separators.py
imports: import unittest
  from igraph import Graph, InternalError
label_desc: Use image node_id 1 for calling a global function with example usage: powerset(iterable) without return types