code: def calculate_laplacian(adj):
      D = np.diag(np.ravel(adj.sum(axis=0)) ** (-0.5))
      adj = np.dot(D, np.dot(adj, D))
      return adj
  
file_path: stellargraph/stellargraph/core/utils.py
imports: import collections
  import scipy.sparse
  from scipy.sparse.linalg import ArpackNoConvergence, eigsh
  import numpy
label_desc: Use image node_id 7 for calling a global function with example usage: calculate_laplacian(adj) and returns: adj