code: def _all_registered_ops():
      """Return the set of the names of all registered operators"""
      return _cpu_ops.union(_gpu_ops).union(_mixed_ops)
  
file_path: DALI/dali/python/nvidia/dali/ops/_registry.py
imports: from nvidia.dali import backend
label_desc: Use image node_id 4 for calling a global function with example usage: _all_registered_ops() and returns: _cpu_ops