code: def to_set(edge_index):
      return set([(i, j) for i, j in edge_index.t().tolist()])
  
imports: import warnings
  import torch
  from torch_geometric.nn import approx_knn, approx_knn_graph
  from torch_geometric.testing import onlyFullTest, withPackage
label_desc: Use image node_id 1 for calling a global function with example usage: to_set(edge_index) and returns: set