code: def __call__(self, sample_info):
      return np.int32([42])
  
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 1 for calling the DummyCb42 obj's underlying member method code with example usage: obj.__call__(sample_info) and returns: np