class_docstr: Tests for purity transform
docstr: Tests purity for a qnode without parameters
docstr_tok: ["Tests","purity","for","a","qnode","without","parameters"]
code: def test_IsingXX_qnode_purity_no_params(
      self, device, wires, is_partial
  ):
      """Tests purity for a qnode without parameters"""
  
      dev = qml.device(device, wires=2)
  
      @qml.qnode(dev)
      def circuit_state():
          qml.IsingXX(0, wires=[0, 1])
          return qml.state()
  
      purity = qml.qinfo.purity(circuit_state, wires=wires)()
      expected_purity = expected_purity_ising_xx(0) if is_partial else 1
      assert qml.math.allclose(purity, expected_purity)
  
imports: import pytest
  import pennylane
  from pennylane import numpy
label_desc: Use image node_id 4 for calling the TestPurity obj's underlying member method code with example usage: obj.test_IsingXX_qnode_purity_no_params(device, wires, is_partial) and returns: qml