code: def compute_ndcg(
      sum_ndcg: torch.Tensor, num_sessions: torch.Tensor
  ) -> torch.Tensor:
      return sum_ndcg / num_sessions
  
imports: from typing import Any, cast, Dict, List, Optional, Type
  import torch
  from torch import distributed
  from torchrec.metrics.metrics_config import RecComputeMode, RecTaskInfo
  from torchrec.metrics.metrics_namespace import MetricName, MetricNamespace, MetricPrefix
  from torchrec.metrics.rec_metric import MetricComputationReport, RecMetric, RecMetricComputation, RecMetricException
label_desc: Use image node_id 7 for calling a global function with example usage: compute_ndcg(sum_ndcg, num_sessions) and returns: unknown