code: def test_unchanged():
      assert unchanged(MatPow, C, 0)
      assert unchanged(MatPow, C, 1)
      assert unchanged(MatPow, Inverse(C), -1)
      assert unchanged(Inverse, MatPow(C, -1), -1)
      assert unchanged(MatPow, MatPow(C, -1), -1)
      assert unchanged(MatPow, MatPow(C, 1), 1)
  
imports: from sympy.functions.elementary.miscellaneous import sqrt
  from sympy.simplify.powsimp import powsimp
  from sympy.testing.pytest import raises
  from sympy.core.expr import unchanged
  from sympy.core import symbols, S
  from sympy.matrices import Identity, MatrixSymbol, ImmutableMatrix, ZeroMatrix, OneMatrix, Matrix
  from sympy.matrices.exceptions import NonSquareMatrixError
  from sympy.matrices.expressions import MatPow, MatAdd, MatMul
  from sympy.matrices.expressions.inverse import Inverse
  from sympy.matrices.expressions.matexpr import MatrixElement
label_desc: Use image node_id 16 for calling a global function with example usage: test_unchanged() without return types