docstr: Test that the dictionary keys *all* eigenvalues of the observable,
  including 0 count values, if observable is given and all_outcomes=True
docstr_tok: ["Test","that","the","dictionary","keys","*","all","*","eigenvalues","of","the","observable",",","including","0","count","values",",","if","observable","is","given","and","all_outcomes=True"]
code: def test_all_outcomes_kwarg_providing_observable(self, mocker):
      """Test that the dictionary keys *all* eigenvalues of the observable,
      including 0 count values, if observable is given and all_outcomes=True
      """
  
      n_shots = 10
      dev = qml.device("default.qubit.legacy", wires=1, shots=n_shots)
      spy = mocker.spy(qml.QubitDevice, "sample")
  
      @qml.qnode(dev)
      def circuit():
          res = qml.counts(qml.PauliZ(0), all_outcomes=True)
          return res
  
      res = circuit()
  
      assert res == {1: n_shots, -1: 0}
  
      custom_measurement_process(dev, spy)
  
imports: import numpy
  import pytest
  import pennylane
  from pennylane.measurements import Counts
  from pennylane.operation import Operator
label_desc: Use image node_id 23 for calling the TestCountsIntegration obj's underlying member method code with example usage: obj.test_all_outcomes_kwarg_providing_observable(mocker) and returns: res