code: def test_is_isolate():
      G = nx.Graph()
      G.add_edge(0, 1)
      G.add_node(2)
      assert not nx.is_isolate(G, 0)
      assert not nx.is_isolate(G, 1)
      assert nx.is_isolate(G, 2)
  
imports: import networkx
label_desc: Use image node_id 1 for calling a global function with example usage: test_is_isolate() without return types