code: def test_blockmodel():
      G = nx.path_graph(6)
      partition = [[0, 1], [2, 3], [4, 5]]
      M = nx.quotient_graph(G, partition, relabel=True)
      assert nodes_equal(M.nodes(), [0, 1, 2])
      assert edges_equal(M.edges(), [(0, 1), (1, 2)])
      for n in M.nodes():
          assert M.nodes[n]["nedges"] == 1
          assert M.nodes[n]["nnodes"] == 2
          assert M.nodes[n]["density"] == 1.0
  
imports: import pytest
  import networkx
  from networkx.utils import arbitrary_element, edges_equal, nodes_equal
label_desc: Use image node_id 16 for calling a global function with example usage: test_blockmodel() without return types