code: def _test_combinations_comm():
      assert set(allcombinations((1, 2, 3), (a, b), None)) == {
          (((1,), (2, 3)), ("a", "b")),
          (((2,), (3, 1)), ("a", "b")),
          (((3,), (1, 2)), ("a", "b")),
          (((1, 2), (3,)), ("a", "b")),
          (((2, 3), (1,)), ("a", "b")),
          (((3, 1), (2,)), ("a", "b")),
      }
  
file_path: sympy/sympy/unify/tests/test_unify.py
imports: from sympy.unify.core import Compound, Variable, CondVariable, allcombinations
  from sympy.unify import core
label_desc: Use image node_id 9 for calling a global function with example usage: _test_combinations_comm() without return types