code: def test_edmonds2_maxarbor():
      G = G2()
      x = branchings.maximum_spanning_arborescence(G)
      x_ = build_branching(optimal_arborescence_2)
      assert_equal_branchings(x, x_)
  
imports: import math
  from operator import itemgetter
  import pytest
  import networkx
  from networkx.algorithms.tree import branchings, recognition
label_desc: Use image node_id 22 for calling a global function with example usage: test_edmonds2_maxarbor() without return types