code: def test_cycle_c4_directed(self):
      c = harmonic_centrality(
          self.C4_directed, nbunch=[0, 1], sources=[1, 2]
      )
      d = {0: 0.833, 1: 0.333}
      for n in [0, 1]:
          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 12 for calling the TestClosenessCentrality obj's underlying member method code with example usage: obj.test_cycle_c4_directed() without return types