Recursive AssertCountEqual in unittest

Question

I am writing a simple test for a function that should take as input an iterable and produce a list of all possible partitions of the input:

def partitions(collection):
  """ Iterator over partitions of collection
      https://stackoverflow.com/a/30134039/4841832
  """
  if len(collection) == 1:
    yield [ collection ]
    return

  first = collection[0]
  for smaller in partitions(collection[1:]):
    # insert `first` in each of the subpartition's subsets
    for n, subset in enumerate(smaller):
      yield smaller[:n] + [[ first ] + subset]  + smaller[n+1:]
    # put `first` in its own subset 
    yield [ [ first ] ] + smaller

I tried using assertCountEquals for my test, but this does not work - it only checks for surface level similarity of the containers, instead of the 2 level similarity I need for my function.

def test_partitions(self):
      s = list(partitions([1,2,3]))
      self.assertCountEqual(s, [
        [[1,2,3]],
        [[1], [2,3]],
        [[2], [1,3]],
        [[3], [1,2]],
        [[1], [2], [3]]
      ])

======================================================================
FAIL: test_partitions (explainbn.test.test_utilities.TestIterationUtilities)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "...\test\test_utilities.py", line 124, in test_partitions
    self.assertCountEqual(s, [
AssertionError: Element counts were not equal:
First has 1, Second has 0:  [[1, 2], [3]]
First has 0, Second has 1:  [[3], [1, 2]]

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What is the best way to write the test to achieve what I want? I don't care about the order of the elements or the type of the containers.