code: def test_single_channel(self):
      samples = np.random.normal(0, 0.1, size=(2048,)).astype(
          np.float32
      )
      sample_rate = 16000
      augmenter = TanhDistortion(
          min_distortion=0.2, max_distortion=0.6, p=1.0
      )
  
      distorted_samples = augmenter(
          samples=samples, sample_rate=sample_rate
      )
  
      assert samples.dtype == distorted_samples.dtype
      assert samples.shape == distorted_samples.shape
      assert np.amax(distorted_samples) < np.amax(samples)
      assert calculate_rms(distorted_samples) == pytest.approx(
          calculate_rms(samples), abs=1e-3
      )
  
imports: import numpy
  import pytest
  from audiomentations import TanhDistortion
  from audiomentations.core.utils import calculate_rms
label_desc: Use image node_id 1 for calling the TestTanhDistortion obj's underlying member method code with example usage: obj.test_single_channel() without return types