code: def vocab_size(self):
      return self._vocab_size
  
imports: from dataclasses import dataclass
  from typing import Dict, Optional
  import torch
  from omegaconf.omegaconf import MISSING
  from nemo.collections.asr.modules.transformer.decoder_module import DecoderModule
  from nemo.collections.asr.modules.transformer.encoder_module import EncoderModule
  from nemo.collections.asr.modules.transformer.transformer_decoders import TransformerDecoder
  from nemo.collections.asr.modules.transformer.transformer_encoders import TransformerEncoder
  from nemo.collections.asr.modules.transformer.transformer_modules import TransformerEmbedding
  from nemo.core.classes.common import typecheck
  from nemo.core.classes.exportable import Exportable
  from nemo.core.neural_types import ChannelType, NeuralType
label_desc: Use image node_id 4 for calling the TransformerDecoderNM obj's underlying member method code with example usage: obj.vocab_size() and returns: self