code: def test_three_sum(self):
      self.assertSetEqual(
          three_sum([-1, 0, 1, 2, -1, -4]), {(-1, 0, 1), (-1, -1, 2)}
      )
  
      self.assertSetEqual(
          three_sum([-1, 3, 1, 2, -1, -4, -2]),
          {(-4, 1, 3), (-2, -1, 3), (-1, -1, 2)},
      )
  
imports: from algorithms.arrays import delete_nth, delete_nth_naive, flatten_iter, flatten, garage, josephus, longest_non_repeat_v1, longest_non_repeat_v2, get_longest_non_repeat_v1, get_longest_non_repeat_v2, Interval, merge_intervals, missing_ranges, move_zeros, plus_one_v1, plus_one_v2, plus_one_v3, rotate_v1, rotate_v2, rotate_v3, summarize_ranges, three_sum, two_sum, max_ones_index, trimmean, top_1, limit, n_sum
  import unittest
label_desc: Use image node_id 1 for calling the TestThreeSum obj's underlying member method code with example usage: obj.test_three_sum() without return types