code: def define_graph(self):
      self.data = self.inputs()
      mel_fbank = (
          self._transposed(self.mel_fbank)
          if self.need_transpose
          else self.mel_fbank
      )
      out = mel_fbank(self.data)
      return out
  
imports: from nvidia.dali.pipeline import Pipeline
  import nvidia.dali.ops
  import numpy
  from functools import partial
  from test_utils import compare_pipelines
  from test_utils import RandomlyShapedDataIterator
  import librosa
label_desc: Use image node_id 3 for calling the MelFilterBankPythonPipeline obj's underlying member method code with example usage: obj.define_graph() and returns: out