code: def test_unequal_replace_field_at_indices(self):
      # test insert before index and mask
      ins_aft = nli_sample.unequal_replace_field_at_indices(
          "premise", [2], [["$$$", "123"]]
      )
      self.assertEqual(
          "Mr zhang $$$ 123 20 students", ins_aft.get_text("premise")
      )
      self.assertEqual(ins_aft.y.field_value, "contradiction")
      self.assertEqual([0, 0, 2, 2, 0, 0], ins_aft.get_mask("premise"))
  
file_path: textflint/test/input/component/sample/test_nli_sample.py
imports: import unittest
  from textflint.input.component.sample.nli_sample import *
label_desc: Use image node_id 3 for calling the TestNLISample obj's underlying member method code with example usage: obj.test_unequal_replace_field_at_indices() without return types