code: def define_graph(self):
      self.data = self.inputs()
      out = self.spectrogram(self.data)
      return out
  
imports: from nvidia.dali.pipeline import Pipeline
  import nvidia.dali.ops
  import nvidia.dali.types
  import nvidia.dali
  import numpy
  from functools import partial
  from test_utils import get_files
  from test_utils import compare_pipelines
  from test_utils import RandomDataIterator
  from test_utils import ConstantDataIterator
  import librosa
  import math
label_desc: Use image node_id 2 for calling the SpectrogramPythonPipeline obj's underlying member method code with example usage: obj.define_graph() and returns: out