class_docstr: Test the qml.qsvt function.
class_docstr_tok: ["Test","the","qml.qsvt","function","."]
docstr: Test that qml.qsvt produces the correct output.
docstr_tok: ["Test","that","qml.qsvt","produces","the","correct","output","."]
code: def test_output(self, A, phis, wires, true_mat):
      """Test that qml.qsvt produces the correct output."""
      dev = qml.device("default.qubit", wires=len(wires))
  
      @qml.qnode(dev)
      def circuit():
          qml.qsvt(A, phis, wires)
          return qml.expval(qml.PauliZ(wires=0))
  
      observable_mat = np.kron(qml.matrix(qml.PauliZ(0)), np.eye(2))
      true_expval = (np.conj(true_mat).T @ observable_mat @ true_mat)[
          0, 0
      ]
  
      assert np.isclose(circuit(), true_expval)
      assert np.allclose(qml.matrix(circuit)(), true_mat)
  
imports: import pytest
  import pennylane
  from pennylane import numpy
label_desc: Use image node_id 1 for calling the Testqsvt obj's underlying member method code with example usage: obj.test_output(A, phis, wires, true_mat) and returns: qml