code: def test_doit_symbol():
      assert MatPow(C, 0).doit() == Identity(n)
      assert MatPow(C, 1).doit() == C
      assert MatPow(C, -1).doit() == C.I
      for r in [2, S.Half, S.Pi, n]:
          assert MatPow(C, r).doit() == MatPow(C, r)
  
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 5 for calling a global function with example usage: test_doit_symbol() without return types