code: def test_unconnected_communities():
      test = nx.Graph()
      # community 1
      test.add_edge("a", "c")
      test.add_edge("a", "d")
      test.add_edge("d", "c")
      # community 2
      test.add_edge("b", "e")
      test.add_edge("e", "f")
      test.add_edge("f", "b")
  
      # The expected communities are:
      ground_truth = {
          frozenset(["a", "c", "d"]),
          frozenset(["b", "e", "f"]),
      }
  
      communities = nx.community.label_propagation_communities(test)
      result = {frozenset(c) for c in communities}
      assert result == ground_truth
  
imports: from itertools import chain, combinations
  import pytest
  import networkx
label_desc: Use image node_id 4 for calling a global function with example usage: test_unconnected_communities() without return types