code: def test_single_number2(self):
      self.assertEqual(
          3, single_number2([4, 2, 3, 2, 1, 1, 4, 2, 4, 1])
      )
      single = random.randint(1, 100000)
      nums = [random.randint(1, 100000) for _ in range(1000)]
      nums *= 3  # nums contains triplets of random integers
      nums.append(single)
      random.shuffle(nums)
      self.assertEqual(single, single_number2(nums))
  
imports: from algorithms.bit import add_bitwise_operator, count_ones_iter, count_ones_recur, count_flips_to_convert, find_missing_number, find_missing_number2, flip_bit_longest_seq, is_power_of_two, reverse_bits, single_number, single_number2, single_number3, subsets, get_bit, set_bit, clear_bit, update_bit, int_to_bytes_big_endian, int_to_bytes_little_endian, bytes_big_endian_to_int, bytes_little_endian_to_int, swap_pair, find_difference, has_alternative_bit, has_alternative_bit_fast, insert_one_bit, insert_mult_bits, remove_bit, binary_gap
  import unittest
  import random
label_desc: Use image node_id 12 for calling the TestSuite obj's underlying member method code with example usage: obj.test_single_number2() without return types