class_docstr: Tests for the (reduced) density matrix for QNodes returning states.
docstr: Test reduced_dm jitting for QNode.
docstr_tok: ["Test","reduced_dm","jitting","for","QNode","."]
code: def test_density_matrix_qnode_jax_jit(self, tol):
      """Test reduced_dm jitting for QNode."""
      import jax.numpy as jnp
      from jax import jit
  
      angle = jnp.array(0.1)
  
      dev = qml.device("default.qubit", wires=2)
  
      @qml.qnode(dev, interface="jax-jit")
      def circuit(x):
          qml.IsingXX(x, wires=[0, 1])
          return qml.state()
  
      density_matrix = jit(qml.qinfo.reduced_dm(circuit, wires=[0]))(
          angle
      )
      expected_density_matrix = [
          [np.cos(angle / 2) ** 2, 0],
          [0, np.sin(angle / 2) ** 2],
      ]
  
      assert np.allclose(
          density_matrix, expected_density_matrix, atol=tol, rtol=0
      )
  
file_path: pennylane/tests/qinfo/test_reduced_dm.py
imports: import pytest
  import pennylane
  from pennylane import numpy
label_desc: Use image node_id 5 for calling the TestDensityMatrixQNode obj's underlying member method code with example usage: obj.test_density_matrix_qnode_jax_jit(tol) and returns: qml