code: def test_one_labeled_node(self):
      G = nx.path_graph(4)
      label_name = "label"
      G.nodes[0][label_name] = "A"
      predicted = node_classification.harmonic_function(
          G, label_name=label_name
      )
      assert predicted[0] == "A"
      assert predicted[1] == "A"
      assert predicted[2] == "A"
      assert predicted[3] == "A"
  
file_path: networkx/networkx/algorithms/tests/test_node_classification.py
imports: import pytest
  import networkx
  from networkx.algorithms import node_classification
label_desc: Use image node_id 6 for calling the TestHarmonicFunction obj's underlying member method code with example usage: obj.test_one_labeled_node() without return types