code: def test_background_short_file():
      D = muda.deformers.BackgroundNoise(files="tests/data/fixture.wav")
      jam_orig = muda.load_jam_audio(
          "tests/data/fixture.jams", "tests/data/noise_sample.ogg"
      )
      jam_new = next(D.transform(jam_orig))
  
imports: from copy import deepcopy
  import re
  import six
  import numpy
  import soundfile
  import jams
  import librosa
  import muda
  import pytest
  import scipy
  from contextlib import contextmanager
label_desc: Use image node_id 30 for calling a global function with example usage: test_background_short_file() without return types