code: def test_christofides_ignore_selfloops():
      G = nx.complete_graph(5)
      G.add_edge(3, 3)
      cycle = nx_app.christofides(G)
      assert len(cycle) - 1 == len(G) == len(set(cycle))
  
imports: import random
  import pytest
  import networkx
  import networkx.algorithms.approximation
label_desc: Use image node_id 3 for calling a global function with example usage: test_christofides_ignore_selfloops() without return types