code: def _ranking_reduce(score: Tensor, num_elements: int) -> Tensor:
      return score / num_elements
  
file_path: torchmetrics/src/torchmetrics/functional/classification/ranking.py
imports: from typing import Optional, Tuple
  import torch
  from torch import Tensor
  from torchmetrics.functional.classification.confusion_matrix import _multilabel_confusion_matrix_arg_validation, _multilabel_confusion_matrix_format, _multilabel_confusion_matrix_tensor_validation
  from torchmetrics.utilities.data import _cumsum
label_desc: Use image node_id 2 for calling a global function with example usage: _ranking_reduce(score, num_elements) and returns: unknown