code: def test_nonhashable_node(self):
      # Test if a non-hashable object is in the Graph.  A python dict will
      # raise a TypeError, but for a Graph class a simple  False should be
      # returned (see Graph __contains__). If it cannot be a node then it is
      # not a node.
      G = self.G()
      assert not G.has_node(["A"])
      assert not G.has_node({"A": 1})
  
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 4 for calling the HistoricalTests obj's underlying member method code with example usage: obj.test_nonhashable_node() without return types