code: def test_cycle_C4(self):
      c = harmonic_centrality(self.C4)
      d = {0: 2.5, 1: 2.5, 2: 2.5, 3: 2.5}
      for n in sorted(self.C4):
          assert c[n] == pytest.approx(d[n], abs=1e-3)
  
file_path: networkx/networkx/algorithms/centrality/tests/test_harmonic_centrality.py
imports: import pytest
  import networkx
  from networkx.algorithms.centrality import harmonic_centrality
label_desc: Use image node_id 5 for calling the TestClosenessCentrality obj's underlying member method code with example usage: obj.test_cycle_C4() without return types