code: def test_normalized_laplacian():
      _check_op(convolution.normalized_laplacian, adj, symmetric=False)
      _check_op(convolution.normalized_laplacian, adj, symmetric=True)
  
imports: import networkx
  import numpy
  import pytest
  import scipy.sparse
  from spektral.utils import convolution
label_desc: Use image node_id 9 for calling a global function with example usage: test_normalized_laplacian() without return types