code: def test_single_node(self):
      G = nx.empty_graph(1)
      ground_truth = {frozenset([0])}
      self._check_communities(G, ground_truth)
  
imports: from itertools import chain, combinations
  import pytest
  import networkx
label_desc: Use image node_id 3 for calling the TestAsynLpaCommunities obj's underlying member method code with example usage: obj.test_single_node() without return types