code: def decode_all(self, z):
      prob_adj = z @ z.t()
      return (prob_adj > 0).nonzero(as_tuple=False).t()
  
file_path: pytorch_geometric/examples/link_pred.py
imports: import os.path
  import torch
  from sklearn.metrics import roc_auc_score
  import torch_geometric.transforms
  from torch_geometric.datasets import Planetoid
  from torch_geometric.nn import GCNConv
  from torch_geometric.utils import negative_sampling
label_desc: Use image node_id 4 for calling the Net obj's underlying member method code with example usage: obj.decode_all(z) and returns: unknown