class_docstr: Sentence (or sentence pair) prediction (classification or regression) task.
  
  Args:
      dictionary (Dictionary): the dictionary for the input of the task
code: def build_model(self, cfg, from_checkpoint=False):
      from fairseq import models
  
      with open_dict(cfg) if OmegaConf.is_config(
          cfg
      ) else contextlib.ExitStack():
          cfg.max_positions = self.cfg.max_positions
  
      model = models.build_model(cfg, self, from_checkpoint)
  
      model.register_classification_head(
          self.cfg.classification_head_name,
          num_classes=self.cfg.num_classes,
      )
  
      return model
  
imports: import logging
  import os
  import contextlib
  from dataclasses import dataclass, field
  from typing import Optional
  from omegaconf import MISSING, II, open_dict, OmegaConf
  import numpy
  from fairseq.data import ConcatSentencesDataset, Dictionary, IdDataset, NestedDictionaryDataset, NumelDataset, NumSamplesDataset, OffsetTokensDataset, PrependTokenDataset, RawLabelDataset, RightPadDataset, RightPaddingMaskDataset, RollDataset, SortDataset, StripTokenDataset, data_utils
  from fairseq.data.shorten_dataset import maybe_shorten_dataset
  from fairseq.tasks import FairseqDataclass, FairseqTask, register_task
  from fairseq.dataclass import ChoiceEnum
label_desc: Use image node_id 5 for calling the SentencePredictionTask obj's underlying member method code with example usage: obj.build_model(cfg, from_checkpoint) and returns: model