code: def test_contraction_structure_Pow_in_Pow():
      x = IndexedBase("x")
      y = IndexedBase("y")
      z = IndexedBase("z")
      i, j, k = Idx("i"), Idx("j"), Idx("k")
      ii_jj_kk = x[i, i] ** y[j, j] ** z[k, k]
      expected = {
          None: {ii_jj_kk},
          ii_jj_kk: [
              {(i,): {x[i, i]}},
              {
                  None: {y[j, j] ** z[k, k]},
                  y[j, j]
                  ** z[k, k]: [{(j,): {y[j, j]}}, {(k,): {z[k, k]}}],
              },
          ],
      }
      assert get_contraction_structure(ii_jj_kk) == expected
  
imports: from sympy.core import symbols, S, Pow, Function
  from sympy.functions import exp
  from sympy.testing.pytest import raises
  from sympy.tensor.indexed import Idx, IndexedBase
  from sympy.tensor.index_methods import IndexConformanceException
  from sympy.tensor.index_methods import get_contraction_structure, get_indices
label_desc: Use image node_id 14 for calling a global function with example usage: test_contraction_structure_Pow_in_Pow() without return types