class_docstr: Asteroid Filterbank Frontend.
  
  Provides a Sinc-convolutional-based audio feature extractor. The same
  function can be achieved by using `sliding_winodw frontend +
  sinc preencoder`.
  
  NOTE(jiatong): this function is used in sentence-level classification
  tasks (e.g., spk). Other usages are not fully investigated.
  
  NOTE(jeeweon): this function implements the parameterized analytic
  filterbank layer in M. Pariente, S. Cornell, A. Deleforge and E. Vincent,
  "Filterbank design for end-to-end speech separation," in Proc. ICASSP, 2020
docstr: Return output length of feature dimension D.
code: def output_size(self) -> int:
      """Return output length of feature dimension D."""
      return self.sinc_filters
  
file_path: espnet/espnet2/asr/frontend/asteroid_frontend.py
imports: from typing import Tuple
  import torch
  import torch.nn
  import torch.nn.functional
  from asteroid_filterbanks import Encoder, ParamSincFB
  from typeguard import check_argument_types
  from espnet2.asr.frontend.abs_frontend import AbsFrontend
label_desc: Use image node_id 3 for calling the AsteroidFrontend obj's underlying member method code with example usage: obj.output_size() and returns: self