code: def test_search_by_vector(self):
      f = 2
      i = HnswIndex(f, "L2")
      i.add_data([2, 2])
      i.add_data([3, 2])
      i.add_data([3, 3])
      i.build()
  
      self.assertEqual(i.search_by_vector([4, 4], 3), [2, 1, 0])
      self.assertEqual(i.search_by_vector([1, 1], 3), [0, 1, 2])
      self.assertEqual(i.search_by_vector([4, 2], 3), [1, 2, 0])
  
imports: import unittest
  import random
  import os
  from n2 import HnswIndex
label_desc: Use image node_id 1 for calling the L2Test obj's underlying member method code with example usage: obj.test_search_by_vector() without return types