class_docstr: An abstract class to fuse different models' features (single-modal and multimodal).
code: def label_key(self):
      pass
  
file_path: autogluon/multimodal/src/autogluon/multimodal/models/fusion/base.py
imports: import logging
  from abc import ABC, abstractclassmethod, abstractmethod
  from typing import Optional
  from torch import nn
  from ...constants import AUTOMM, LABEL
label_desc: Use image node_id 2 for calling the AbstractMultimodalFusionModel obj's underlying member method code with example usage: obj.label_key() without return types