docstr: Test closer_than returns expected value for distinct and identical nodes.
code: def test_closer_than(self):
      """Test closer_than returns expected value for distinct and identical nodes."""
      self.assertEqual(
          self.vectors.closer_than("dog.n.01", "dog.n.01"), []
      )
      expected = set(["canine.n.02", "hunting_dog.n.01"])
      self.assertEqual(
          set(self.vectors.closer_than("dog.n.01", "carnivore.n.01")),
          expected,
      )
  
imports: import logging
  import os
  import tempfile
  import unittest
  import numpy
  from gensim.models.poincare import PoincareRelations, PoincareModel, PoincareKeyedVectors
  from gensim.test.utils import datapath
label_desc: Use image node_id 20 for calling the TestPoincareKeyedVectors obj's underlying member method code with example usage: obj.test_closer_than() without return types