code: def test_apply_mp3_compression_low_bitrate(
      self, backend: str, shape: tuple
  ):
      samples_in = np.random.normal(0, 1, size=shape).astype(np.float32)
      sample_rate = 16000
      augmenter = Mp3Compression(
          p=1.0, min_bitrate=8, max_bitrate=8, backend=backend
      )
  
      samples_out = augmenter(
          samples=samples_in, sample_rate=sample_rate
      )
      assert len(shape) == len(samples_out.shape)
      assert samples_out.dtype == np.float32
      assert samples_out.shape[-1] >= shape[-1]
      assert samples_out.shape[-1] < shape[-1] + 3100
      if len(shape) == 2:
          assert samples_out.shape[0] == shape[0]
  
file_path: audiomentations/tests/test_mp3_compression.py
imports: import os
  import matplotlib.pyplot
  import numpy
  import pytest
  from audiomentations import Mp3Compression
  from audiomentations.core.audio_loading_utils import load_sound_file
  from demo.demo import DEMO_DIR
label_desc: Use image node_id 2 for calling the TestMp3Compression obj's underlying member method code with example usage: obj.test_apply_mp3_compression_low_bitrate(backend, shape) without return types