code: def __init__(
      self, task, ranking_head_name, save_predictions, num_classes
  ):
      super().__init__(task)
      self.ranking_head_name = ranking_head_name
      if save_predictions is not None:
          self.prediction_h = open(save_predictions, "w")
      else:
          self.prediction_h = None
      self.num_classes = num_classes
  
file_path: fairseq/fairseq/criterions/sentence_ranking.py
imports: import math
  import torch
  import torch.nn.functional
  from fairseq import utils
  from fairseq.logging import metrics
  from fairseq.criterions import FairseqCriterion, register_criterion
label_desc: Use image node_id 1 to create a new SentenceRankingCriterion object from inherited base classes: FairseqCriterion with example: obj = SentenceRankingCriterion(task, ranking_head_name, save_predictions, num_classes)