code: def _singular_quat_to_zyz(qw, qx, qy, qz, y_arg, abstract_jax=False):
      """Compute the ZYZ angles for the singular case of qx = qy = 0"""
      # pylint: disable=too-many-arguments
      z1_arg1 = 2 * (qx * qy + qz * qw)
      z1_arg2 = 1 - 2 * (qx**2 + qz**2)
  
      if abstract_jax:
          from jax.lax import cond
  
          return cond(
              y_arg > 0,
              lambda z1_arg1, z1_arg2: stack(
                  [arctan2(z1_arg1, z1_arg2), 0.0, 0.0]
              ),
              lambda z1_arg1, z1_arg2: stack(
                  [-arctan2(z1_arg1, z1_arg2), np.pi, 0.0]
              ),
              z1_arg1,
              z1_arg2,
          )
  
      if y_arg > 0:
          z1 = arctan2(z1_arg1, z1_arg2)
          y = z2 = 0.0
      else:
          z1 = -arctan2(z1_arg1, z1_arg2)
          y = np.pi
          z2 = 0.0
      return stack([z1, y, z2])
  
file_path: pennylane/pennylane/transforms/optimization/optimization_utils.py
imports: from functools import partial
  import numpy
  from pennylane.math import abs
  from pennylane.math import sum
  from pennylane.math import allclose, arccos, arctan2, cos, get_interface, is_abstract, sin, stack
  from pennylane.wires import Wires
  from pennylane.ops.identity import GlobalPhase
label_desc: Use image node_id 4 for calling a global function with example usage: _singular_quat_to_zyz(qw, qx, qy, qz, y_arg, abstract_jax) and returns: stack, cond