code: def test_laplacian_lambda_max():
      N = 20
      eps = 1e-6
      # test DGLGraph
      g = dgl.from_networkx(nx.erdos_renyi_graph(N, 0.3))
      l_max = dgl.laplacian_lambda_max(g)
      assert l_max[0] < 2 + eps
      # test batched DGLGraph
      """
      N_arr = [20, 30, 10, 12]
      bg = dgl.batch([
          dgl.from_networkx(nx.erdos_renyi_graph(N, 0.3))
          for N in N_arr
      ])
      l_max_arr = dgl.laplacian_lambda_max(bg)
      assert len(l_max_arr) == len(N_arr)
      for l_max in l_max_arr:
          assert l_max < 2 + eps
      """
  
imports: import math
  import os
  import unittest
  import backend
  import dgl
  import dgl.function
  import dgl.partition
  import networkx
  import numpy
  import pytest
  from scipy import sparse
  from utils import parametrize_idtype
  from utils.graph_cases import get_cases
label_desc: Use image node_id 15 for calling a global function with example usage: test_laplacian_lambda_max() without return types