code: def _fuse(angles_1, angles_2, abstract_jax=False):
      """Perform fusion of two angle sets. Separated out so we can do JIT with conditionals."""
      # Compute the product of the quaternions
      qw, qx, qy, qz = _quaternion_product(
          _zyz_to_quat(angles_1), _zyz_to_quat(angles_2)
      )
  
      # Convert the product back into the angles fed to Rot
      y_arg = 1 - 2 * (qx**2 + qy**2)
  
      # Require special treatment of the case qx = qy = 0. Note that we have to check
      # for "greater than" as well, because of imprecisions
      if abstract_jax:
          from jax.lax import cond
  
          return cond(
              math_abs(y_arg) >= 1,
              partial(_singular_quat_to_zyz, abstract_jax=True),
              _regular_quat_to_zyz,
              qw,
              qx,
              qy,
              qz,
              y_arg,
          )
  
      # Require special treatment of the case qx = qy = 0
      if (
          abs(y_arg) >= 1
      ):  # Have to check for "greater than" as well, because of imprecisions
          return _singular_quat_to_zyz(qw, qx, qy, qz, y_arg)
      return _regular_quat_to_zyz(qw, qx, qy, qz, y_arg)
  
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 6 for calling a global function with example usage: _fuse(angles_1, angles_2, abstract_jax) and returns: _regular_quat_to_zyz, cond, _singular_quat_to_zyz