code: def test_mismatched_mat_decomp():
      """Test that an error is raised if the matrix does not match the decomposition if both are defined."""
  
      class MisMatchedMatDecomp(Operator):
          @staticmethod
          def compute_matrix():
              return np.eye(2)
  
          def decomposition(self):
              return [qml.PauliX(0)]
  
      with pytest.raises(
          AssertionError,
          match=r"matrix and matrix from decomposition must match",
      ):
          assert_valid(MisMatchedMatDecomp(0), skip_pickle=True)
  
imports: import pytest
  import numpy
  import pennylane
  from pennylane.operation import Operator
  from pennylane.ops.functions import assert_valid
label_desc: Use image node_id 1 for calling a global function with example usage: test_mismatched_mat_decomp() and returns: np, list