code: def test_add_operators(self):
      # "123", 6 -> ["1+2+3", "1*2*3"]
      s = "123"
      target = 6
      self.assertEqual(add_operators(s, target), ["1+2+3", "1*2*3"])
      # "232", 8 -> ["2*3+2", "2+3*2"]
      s = "232"
      target = 8
      self.assertEqual(add_operators(s, target), ["2+3*2", "2*3+2"])
  
      s = "123045"
      target = 3
      answer = [
          "1+2+3*0*4*5",
          "1+2+3*0*45",
          "1+2-3*0*4*5",
          "1+2-3*0*45",
          "1-2+3+0-4+5",
          "1-2+3-0-4+5",
          "1*2+3*0-4+5",
          "1*2-3*0-4+5",
          "1*23+0-4*5",
          "1*23-0-4*5",
          "12+3*0-4-5",
          "12-3*0-4-5",
      ]
      self.assertEqual(add_operators(s, target), answer)
  
imports: from algorithms.backtrack import add_operators, permute_iter, anagram, array_sum_combinations, unique_array_sum_combinations, combination_sum, get_factors, recursive_get_factors, find_words, generate_abbreviations, generate_parenthesis_v1, generate_parenthesis_v2, letter_combinations, palindromic_substrings, pattern_match, permute_unique, permute, permute_recursive, subsets_unique, subsets, subsets_v2
  import unittest
label_desc: Use image node_id 1 for calling the TestAddOperator obj's underlying member method code with example usage: obj.test_add_operators() without return types