class_docstr: Tests for Fidelity function between two QNodes.
docstr: Test the gradient of fidelity between Rx and PauliZ circuits with Tensorflow and two parameters.
code: def test_fidelity_qnodes_rx_pauliz_tf_grad_two_params(
      self, param, wire, interface
  ):
      """Test the gradient of fidelity between Rx and PauliZ circuits with Tensorflow and two parameters."""
      import tensorflow as tf
  
      dev = qml.device("default.qubit", wires=wire)
  
      @qml.qnode(dev, interface=interface)
      def circuit0(x):
          qml.RX(x, wires=0)
          return qml.state()
  
      @qml.qnode(dev, interface=interface)
      def circuit1(x):
          qml.RX(x, wires=0)
          qml.RX(-x, wires=0)
          qml.PauliZ(wires=0)
          return qml.state()
  
      expected_fid_grad = expected_grad_fidelity_rx_pauliz(param)
  
      param1 = tf.Variable(param)
      params2 = tf.Variable(0.0)
      with tf.GradientTape() as tape:
          entropy = qml.qinfo.fidelity(
              circuit0, circuit1, wires0=[0], wires1=[0]
          )((param1), (params2))
  
      fid_grad = tape.gradient(entropy, [param1, params2])
      assert qml.math.allclose(fid_grad, (expected_fid_grad, 0.0))
  
imports: import pytest
  import pennylane
  from pennylane import numpy
label_desc: Use image node_id 30 for calling the TestFidelityQnode obj's underlying member method code with example usage: obj.test_fidelity_qnodes_rx_pauliz_tf_grad_two_params(param, wire, interface) and returns: qml, qml