code: def test_unionfind():
      # Fixed by: 2cddd5958689bdecdcd89b91ac9aaf6ce0e4f6b8
      # Previously (in 2.x), the UnionFind class could handle mixed types.
      # But in Python 3.x, this causes a TypeError such as:
      #   TypeError: unorderable types: str() > int()
      #
      # Now we just make sure that no exception is raised.
      x = nx.utils.UnionFind()
      x.union(0, "a")
  
imports: import networkx
label_desc: Use image node_id 1 for calling a global function with example usage: test_unionfind() without return types