code: def define_graph(self):
      self.raw_file = self.file_source()
      dec_plain, rates_plain = self.plain_decoder(self.raw_file)
      dec_res, rates_res = self.resampling_decoder(self.raw_file)
      dec_mix, rates_mix = self.downmixing_decoder(self.raw_file)
      dec_res_mix, rates_res_mix = self.resampling_downmixing_decoder(
          self.raw_file
      )
      out = [
          dec_plain,
          dec_res,
          dec_mix,
          dec_res_mix,
          rates_plain,
          rates_res,
          rates_mix,
          rates_res_mix,
      ]
      return out
  
imports: from nvidia.dali import Pipeline, pipeline_def
  import nvidia.dali.fn
  import nvidia.dali.ops
  import nvidia.dali.types
  import scipy.io.wavfile
  import numpy
  import os
  from test_audio_decoder_utils import generate_waveforms, rosa_resample
  from test_utils import compare_pipelines, get_files
label_desc: Use image node_id 2 for calling the DecoderPipeline obj's underlying member method code with example usage: obj.define_graph() and returns: out