docstr: Test that an error is raised when classical shadows is returned
  with other measurement processes
docstr_tok: ["Test","that","an","error","is","raised","when","classical","shadows","is","returned","with","other","measurement","processes"]
code: def test_multi_measurement_error(self):
      """Test that an error is raised when classical shadows is returned
      with other measurement processes"""
      dev = qml.device("default.qubit.legacy", wires=2, shots=100)
  
      @qml.qnode(dev)
      def circuit():
          qml.Hadamard(wires=0)
          qml.CNOT(wires=[0, 1])
          return qml.shadow_expval(qml.PauliZ(0)), qml.expval(
              qml.PauliZ(0)
          )
  
      msg = "Classical shadows cannot be returned in combination with other return types"
      with pytest.raises(qml.QuantumFunctionError, match=msg):
          _ = circuit()
  
imports: import autograd.numpy
  import pytest
  import pennylane
  from pennylane import numpy
  from pennylane.measurements import Shots
label_desc: Use image node_id 4 for calling the TestExpvalMeasurement obj's underlying member method code with example usage: obj.test_multi_measurement_error() and returns: qml,  qml