code: def test_standard_validity():
      """Run standard checks with the assert_valid function."""
  
      layers = 2
      qubits = 4
  
      weights = np.random.normal(0, 2 * np.pi, (layers, 2 * qubits - 1))
      init_state = np.array([1, 1, 0, 0])
      op = qml.ParticleConservingU2(
          weights, wires=range(qubits), init_state=init_state
      )
      qml.ops.functions.assert_valid(op)
  
imports: import pytest
  import numpy
  import pennylane
  from pennylane import numpy
label_desc: Use image node_id 1 for calling a global function with example usage: test_standard_validity() without return types