code: def test_is_branching_empty_graph_raises():
      G = nx.DiGraph()
      with pytest.raises(
          nx.NetworkXPointlessConcept, match="G has no nodes."
      ):
          nx.is_branching(G)
  
imports: import pytest
  import networkx
label_desc: Use image node_id 5 for calling a global function with example usage: test_is_branching_empty_graph_raises() without return types