code: def test_mutable_list():
      a = MutableList([1, Categorical([1, 2, 3]), 3])
      assert a.default() == [1, 1, 3]
      a.append(Categorical([4, 5, 6]))
      assert a.default() == [1, 1, 3, 4]
  
imports: import math
  from collections import Counter
  import numpy
  import pytest
  from nni.mutable import *
  from nni.mutable.mutable import _dedup_labeled_mutables, _mutable_equal
label_desc: Use image node_id 6 for calling a global function with example usage: test_mutable_list() without return types