code: def max_num_spk(self) -> int:
      raise NotImplementedError
  
file_path: espnet/espnet2/diar/layers/abs_mask.py
imports: from abc import ABC, abstractmethod
  from collections import OrderedDict
  from typing import Tuple
  import torch
label_desc: Use image node_id 1 for calling the AbsMask obj's underlying member method code with example usage: obj.max_num_spk() without return types