code: def forward(self, *args):
      if self.input_names == ("lengths",):
          return self.forward_lengths(*args)
      elif self.input_names == ("lengths", "length_dim"):
          return self.forward_dim(*args)
      elif self.input_names == ("lengths", "maxlen"):
          return self.forward_max(*args)
      elif self.input_names == ("lengths", "length_dim", "maxlen"):
          return self.forward_dim_max(*args)
      elif self.input_names == ("lengths", "xs"):
          return self.forward_xs(*args)
      elif self.input_names == ("lengths", "xs", "length_dim"):
          return self.forward_xs_dim(*args)
  
file_path: espnet/test/test_nets_utils.py
imports: import pytest
  import torch
  from espnet.nets.pytorch_backend.nets_utils import make_pad_mask, trim_by_ctc_posterior
label_desc: Use image node_id 2 for calling the MakePadMaskTest obj's underlying member method code with example usage: obj.forward() and returns: self, self, self, self, self, self