docstr: Test most_similar raises KeyError when input is out of vocab.
code: def test_most_similar_raises_keyerror(self):
      """Test most_similar raises KeyError when input is out of vocab."""
      with self.assertRaises(KeyError):
          self.vectors.most_similar("not_in_vocab")
  
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 4 for calling the TestPoincareKeyedVectors obj's underlying member method code with example usage: obj.test_most_similar_raises_keyerror() without return types