code: def import_numpy():
      global np
      if np is None:
          try:
              import numpy as np
          except ImportError:
              raise RuntimeError(
                  "Could not import numpy. Please make sure you have numpy "
                  "installed before you use parallel mode."
              )
  
imports: import os
  from nvidia.dali._multiproc import shared_mem
  from nvidia.dali._multiproc.messages import ShmMessageDesc
  from nvidia.dali._utils.external_source_impl import assert_cpu_sample_data_type, sample_to_numpy
  import pickle
label_desc: Use image node_id 3 for calling a global function with example usage: import_numpy() without return types