class_docstr: Test that differentiating edge case tapes with ``pulse_odegen`` works.
class_docstr_tok: ["Test","that","differentiating","edge","case","tapes","with","``","pulse_odegen","``","works","."]
docstr: Test that the transform works correctly when the diff method for every parameter is
  identified to be 0, and that no tapes were generated.
docstr_tok: ["Test","that","the","transform","works","correctly","when","the","diff","method","for","every","parameter","is","identified","to","be","0",",","and","that","no","tapes","were","generated","."]
code: def test_all_zero_diff_methods_multiple_returns_tape(self):
      """Test that the transform works correctly when the diff method for every parameter is
      identified to be 0, and that no tapes were generated."""
  
      dev = qml.device("default.qubit", wires=3)
  
      params = pnp.array([0.5, 0.5, 0.5], requires_grad=True)
  
      with qml.queuing.AnnotatedQueue() as q:
          qml.Rot(
              *params, wires=0
          )  # does not impact the measurements -> zero grad
          qml.expval(Z(wires=2))
          qml.probs([2, 3])
  
      tape = qml.tape.QuantumScript.from_queue(q)
  
      res_pulse_gen, _tapes = grad_fn(tape, dev)
  
      assert _tapes == []
  
      assert isinstance(res_pulse_gen, tuple)
  
      assert len(res_pulse_gen) == 2
  
      # First elem
      assert len(res_pulse_gen[0]) == 3
  
      assert isinstance(res_pulse_gen[0][0], np.ndarray)
      assert res_pulse_gen[0][0].shape == ()
      assert np.allclose(res_pulse_gen[0][0], 0)
  
      assert isinstance(res_pulse_gen[0][1], np.ndarray)
      assert res_pulse_gen[0][1].shape == ()
      assert np.allclose(res_pulse_gen[0][1], 0)
  
      assert isinstance(res_pulse_gen[0][2], np.ndarray)
      assert res_pulse_gen[0][2].shape == ()
      assert np.allclose(res_pulse_gen[0][2], 0)
  
      # Second elem
      assert len(res_pulse_gen[0]) == 3
  
      assert isinstance(res_pulse_gen[1][0], np.ndarray)
      assert res_pulse_gen[1][0].shape == (4,)
      assert np.allclose(res_pulse_gen[1][0], 0)
  
      assert isinstance(res_pulse_gen[1][1], np.ndarray)
      assert res_pulse_gen[1][1].shape == (4,)
      assert np.allclose(res_pulse_gen[1][1], 0)
  
      assert isinstance(res_pulse_gen[1][2], np.ndarray)
      assert res_pulse_gen[1][2].shape == (4,)
      assert np.allclose(res_pulse_gen[1][2], 0)
  
imports: import copy
  import pytest
  import numpy
  import pennylane
  from pennylane import numpy
  from pennylane.ops.qubit.special_unitary import pauli_basis_matrices, pauli_basis_strings
  from pennylane.math import expand_matrix
  from pennylane.gradients.pulse_gradient_odegen import _generate_tapes_and_coeffs, pulse_odegen, _insert_op, _nonzero_coeffs_and_words, _one_parameter_generators, _one_parameter_paulirot_coeffs, _parshift_and_contract
label_desc: Use image node_id 8 for calling the TestPulseOdegenEdgeCases obj's underlying member method code with example usage: obj.test_all_zero_diff_methods_multiple_returns_tape() without return types