docstr: Build a new model instance.
code: def build_model(cls, args, task):
      """Build a new model instance."""
      # make sure all arguments are present in older models
      base_lm_architecture(args)
  
      if safe_hasattr(
          args, "max_target_positions"
      ) and not safe_hasattr(args, "tokens_per_sample"):
          args.tokens_per_sample = args.max_target_positions
  
      decoder = FConvDecoder(
          dictionary=task.target_dictionary,
          embed_dim=args.decoder_embed_dim,
          convolutions=eval(args.decoder_layers),
          out_embed_dim=args.decoder_embed_dim,
          attention=eval(args.decoder_attention),
          dropout=args.dropout,
          max_positions=args.tokens_per_sample,
          share_embed=False,
          positional_embeddings=False,
          adaptive_softmax_cutoff=(
              utils.eval_str_list(
                  args.adaptive_softmax_cutoff, type=int
              )
              if args.criterion == "adaptive_loss"
              else None
          ),
          adaptive_softmax_dropout=args.adaptive_softmax_dropout,
      )
      return FConvLanguageModel(decoder)
  
file_path: fairseq/fairseq/models/fconv_lm.py
imports: from fairseq import utils
  from fairseq.models import FairseqLanguageModel, register_model, register_model_architecture
  from fairseq.models.fconv import FConvDecoder
  from fairseq.utils import safe_hasattr
label_desc: Use image node_id 3 for calling the FConvLanguageModel obj's underlying member method code with example usage: obj.build_model(cls, args, task) and returns: FConvLanguageModel