code: def test_spanner_unweighted_disconnected_graph():
      """Test spanner construction on a disconnected graph."""
      G = nx.disjoint_union(
          nx.complete_graph(10), nx.complete_graph(10)
      )
  
      spanner = nx.spanner(G, 4, seed=_seed)
      _test_spanner(G, spanner, 4)
  
      spanner = nx.spanner(G, 10, seed=_seed)
      _test_spanner(G, spanner, 10)
  
file_path: networkx/networkx/algorithms/tests/test_sparsifiers.py
imports: import pytest
  import networkx
  from networkx.utils import py_random_state
label_desc: Use image node_id 8 for calling a global function with example usage: test_spanner_unweighted_disconnected_graph() without return types