title: Assert list of list equality without order in Python
body: <p>What's the best way to assert two lists of lists are equal without importance of order? e.g. these two lists are equal:</p>
  
  <pre><code>a = [[1,2], [3,4]]
  b = [[4,3], [2,1]]
  
  assert lists_equal_without_order(a, b)  # True
  </code></pre>
  
  <p>How can <code>lists_equal_without_order</code> be implemented, ideally with using some of Python's existing assertions?</p>