code: def num_edges(self, edge_type: Tuple[str, str, str]) -> int:
      if edge_type != ("paper", "cites", "paper"):
          raise ValueError(f"Invalid edge type {edge_type}")
  
      return 1_615_685_872 * self.__replication_factor
  
imports: from .dataset import Dataset
  from typing import Dict, Tuple, Union
  import pandas
  import torch
  import numpy
  from sklearn.model_selection import train_test_split
  import gc
  import os
  import json
label_desc: Use image node_id 12 for calling the OGBNPapers100MDataset obj's underlying member method code with example usage: obj.num_edges(edge_type) and returns: unknown