code: def _init_decoder(self):
      embedding = self.text_embeddings[0].module
      embedding_dim = self.text_embeddings[0].embedding_dim
      hidden_dim = self.multi_modal_combine_layer.out_dim
  
      self.decoder = VisDialDiscriminator(
          {"embedding_dim": embedding_dim, "hidden_dim": hidden_dim},
          embedding,
      )
  
file_path: mmf/mmf/models/visdial_multi_modal.py
imports: from mmf.models.pythia import Pythia
  from mmf.modules.decoders import VisDialDiscriminator
label_desc: Use image node_id 6 for calling the VisDialMultiModalModel obj's underlying member method code with example usage: obj._init_decoder() without return types