code: def define_graph(self):
      self.data = self.inputs()
      out = self.oper(self.data)
      return out
  
imports: from nvidia.dali.pipeline import Pipeline
  import nvidia.dali.ops
  from nvidia.dali import fn, pipeline_def
  import math
  from test_utils import compare_pipelines, as_array, RandomDataIterator, RandomlyShapedDataIterator
  import itertools
  from nose2.tools import params
  import numpy
label_desc: Use image node_id 2 for calling the PythonOpPipeline obj's underlying member method code with example usage: obj.define_graph() and returns: out