code: def forward(
      self,
      input: torch.Tensor,
      ilens: torch.Tensor,
  ):
      raise NotImplementedError
  
file_path: espnet/espnet2/enh/diffusion/abs_diffusion.py
imports: from abc import ABC, abstractmethod
  from collections import OrderedDict
  from typing import Dict, Optional, Tuple
  import torch
label_desc: Use image node_id 1 for calling the AbsDiffusion obj's underlying member method code with example usage: obj.forward(input, ilens) without return types