code: def assert_valid_data_type(sample):
      """Check if the output of the callback is type that can be serialized"""
      _apply_to_sample(
          lambda x: _assert_cpu_sample_data_type(x, _sample_error_msg),
          sample,
      )
  
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 7 for calling a global function with example usage: assert_valid_data_type(sample) without return types