code: def create_callback_with_syntactically_nested_code_referencing_global_var():
      def cb_from_closure():
          return 0
  
      def get_data(sample_info):
          def nested_in_cb():
              def super_nested():
                  return (
                      np.fromfile(jpeg_file, dtype=np.uint8)
                      + cb_from_closure()
                  )
  
              return super_nested
  
          return nested_in_cb()()
  
      return get_data
  
imports: import copyreg
  import numpy
  import nvidia.dali.fn
  import nvidia.dali.pickling
  import os
  from nvidia.dali import pipeline_def
  from pickle import PicklingError
  from nose_utils import raises
  from test_utils import get_dali_extra_path, restrict_python_version
label_desc: Use image node_id 15 for calling a global function with example usage: create_callback_with_syntactically_nested_code_referencing_global_var() and returns: get_data, int, nested_in_cb, super_nested, unknown