class_docstr: Gaussian noise applied to padded samples. No
  noise is added to positions that are part of padding
  
  Arguments
  ---------
  length_dim: int
      the
code: def _compute_mask_shape(self, noise, max_len):
      return (
          (noise.shape[0],)
          + (
              (1,) * (self.length_dim - 1)
          )  # Between the batch and len_dim
          + (max_len,)
          + ((1,) * (noise.dim() - 3))  # Unsqueeze at the end
      )
  
imports: from collections import namedtuple
  import torch
  from torch import nn
  from torch.nn import functional
  from tqdm.auto import tqdm
  from speechbrain.utils.data_utils import unsqueeze_as
  from speechbrain.dataio.dataio import length_to_mask
  from speechbrain.utils import data_utils
label_desc: Use image node_id 3 for calling the LengthMaskedGaussianNoise obj's underlying member method code with example usage: obj._compute_mask_shape(noise, max_len) and returns: unknown