code: def test_dummy_sgs():
      a = dummy_sgs([1, 2], 0, 4)
      assert a == [[0, 2, 1, 3, 4, 5]]
      a = dummy_sgs([2, 3, 4, 5], 0, 8)
      assert a == [
          x._array_form
          for x in [Perm(9)(2, 3), Perm(9)(4, 5), Perm(9)(2, 4)(3, 5)]
      ]
  
      a = dummy_sgs([2, 3, 4, 5], 1, 8)
      assert a == [
          x._array_form
          for x in [
              Perm(2, 3)(8, 9),
              Perm(4, 5)(8, 9),
              Perm(9)(2, 4)(3, 5),
          ]
      ]
  
file_path: sympy/sympy/combinatorics/tests/test_tensor_can.py
imports: from sympy.combinatorics.permutations import Permutation, Perm
  from sympy.combinatorics.tensor_can import perm_af_direct_product, dummy_sgs, riemann_bsgs, get_symmetric_group_sgs, canonicalize, bsgs_direct_product
  from sympy.combinatorics.testutil import canonicalize_naive, graph_certificate
  from sympy.testing.pytest import skip, XFAIL
label_desc: Use image node_id 2 for calling a global function with example usage: test_dummy_sgs() without return types