class_docstr: Test functions defined in `functional` module
class_docstr_tok: ["Test","functions","defined","in","`","functional","`","module"]
code: def test_filtfilt(self):
      signal_length = 2048
      x = torch.randn(self.batch_size, signal_length)
      a = torch.rand(self.batch_size, 3)
      b = torch.rand(self.batch_size, 3)
      self.assert_batch_consistency(F.filtfilt, inputs=(x, a, b))
  
imports: import itertools
  import math
  from functools import partial
  import torch
  import torchaudio.functional
  from parameterized import parameterized, parameterized_class
  from torchaudio_unittest import common_utils
label_desc: Use image node_id 15 for calling the TestFunctional obj's underlying member method code with example usage: obj.test_filtfilt() without return types