docstr: Applying delta kernel preserves the origianl waveform
docstr_tok: ["Applying","delta","kernel","preserves","the","origianl","waveform"]
code: def test_filter_waveform_delta(self, num_filters, kernel_size):
      """Applying delta kernel preserves the origianl waveform"""
      waveform = torch.arange(
          -10, 10, dtype=self.dtype, device=self.device
      )
      kernel = torch.zeros(
          (num_filters, kernel_size),
          dtype=self.dtype,
          device=self.device,
      )
      kernel[:, kernel_size // 2] = 1
  
      result = F.filter_waveform(waveform, kernel)
      self.assertEqual(waveform, result)
  
imports: import torch
  import torchaudio.prototype.functional
  from parameterized import param, parameterized
  from torchaudio_unittest.common_utils import nested_params, TestBaseMixin
  from .dsp_utils import exp_sigmoid, freq_ir, oscillator_bank, sinc_ir
label_desc: Use image node_id 11 for calling the FunctionalTestImpl obj's underlying member method code with example usage: obj.test_filter_waveform_delta(num_filters, kernel_size) without return types