code: def _get_positive_indices(self):
      positive_indices_per_question = []
      batch_id, total_ctxs = 0, 0
      batch_size = self.task_batch_size * (1 + self.num_negative_ctxs)
      for i, pos_ctx_idx in enumerate(self.all_targets):
          batch_id = i // self.task_batch_size
          total_ctxs = batch_id * batch_size
          positive_indices_per_question.append(total_ctxs + pos_ctx_idx)
  
      return positive_indices_per_question
  
imports: from enum import Enum
  from typing import Any, Dict, List
  import numpy
  from pytext.common.constants import Stage
  from pytext.metric_reporters.channel import Channel, ConsoleChannel, FileChannel
  from pytext.metric_reporters.metric_reporter import MetricReporter
  from pytext.metrics.dense_retrieval_metrics import DenseRetrievalMetrics
label_desc: Use image node_id 10 for calling the DenseRetrievalMetricReporter obj's underlying member method code with example usage: obj._get_positive_indices() and returns: positive_indices_per_question