code: def define_graph(self):
      encoded_data, _ = self.reader()
      decoded_data = self.decoder(encoded_data)
      out = self.oper(decoded_data)
      return out
  
imports: from nvidia.dali.pipeline import Pipeline
  import nvidia.dali.ops
  import nvidia.dali.types
  import numpy
  import os
  from test_utils import compare_pipelines
  from test_utils import RandomDataIterator
  import cv2
  import glob
label_desc: Use image node_id 2 for calling the MultichannelPythonOpPipeline obj's underlying member method code with example usage: obj.define_graph() and returns: out