code: def test_nbunch_is_set(self):
      G = self.G()
      nbunch = set("ABCDEFGHIJKL")
      G.add_nodes_from(nbunch)
      assert G.has_node("L")
  
imports: import pytest
  import networkx
  from networkx import convert_node_labels_to_integers
  from networkx.utils import edges_equal, nodes_equal
label_desc: Use image node_id 9 for calling the HistoricalTests obj's underlying member method code with example usage: obj.test_nbunch_is_set() without return types