class_docstr: Test suite for classes defined in `transforms` module
class_docstr_tok: ["Test","suite","for","classes","defined","in","`","transforms","`","module"]
code: def test_preemphasis(self):
      waveform = torch.rand(
          (3, 5, 2, 100), dtype=self.dtype, device=self.device
      )
      preemphasis = T.Preemphasis(coeff=0.97)
      actual = preemphasis(waveform)
  
      expected = []
      for i in range(waveform.size(0)):
          for j in range(waveform.size(1)):
              for k in range(waveform.size(2)):
                  expected.append(preemphasis(waveform[i][j][k]))
  
      self.assertEqual(
          torch.stack(expected), actual.reshape(-1, waveform.size(-1))
      )
  
imports: import os
  import torch
  from parameterized import parameterized
  from torchaudio import transforms
  from torchaudio_unittest import common_utils
label_desc: Use image node_id 27 for calling the TestTransforms obj's underlying member method code with example usage: obj.test_preemphasis() without return types