code: def track_time(num_relations):
      dd = {}
      candidate_edges = [
          dgl.data.CoraGraphDataset(verbose=False)[0].edges(),
          dgl.data.PubmedGraphDataset(verbose=False)[0].edges(),
          dgl.data.CiteseerGraphDataset(verbose=False)[0].edges(),
      ]
      for i in range(num_relations):
          dd[("n1", "e_{}".format(i), "n2")] = candidate_edges[
              i % len(candidate_edges)
          ]
  
      # dry run
      graph = dgl.heterograph(dd)
  
      # timing
      with utils.Timer() as t:
          for i in range(3):
              graph = dgl.heterograph(dd)
  
      return t.elapsed_secs / 3
  
imports: import time
  import dgl
  import dgl.function
  import numpy
  import torch
  from ..None import utils
label_desc: Use image node_id 1 for calling a global function with example usage: track_time(num_relations) and returns: unknown