code: def preprocess_adj(adj):
      """Preprocessing of adjacency matrix for simple GCN model and conversion to tuple representation."""
      adj_normalized = normalize_adj(adj + sp.eye(adj.shape[0]))
      return sparse_to_tuple(adj_normalized)
  
file_path: OpenNE/src/openne/gcn/utils.py
imports: import numpy
  import pickle
  import networkx
  import scipy.sparse
  from scipy.sparse.linalg.eigen.arpack import eigsh
  import sys
label_desc: Use image node_id 7 for calling a global function with example usage: preprocess_adj(adj) and returns: sparse_to_tuple