code: def test_insert_field_after_index(self):
      self.assertRaises(
          IndexError, sample.insert_field_after_index, "x", 100, "确实"
      )
      self.assertRaises(
          ValueError, sample.insert_field_after_index, "x", -1, "确实"
      )
      self.assertRaises(
          TypeError, sample.insert_field_after_index, "x", 1.5, "确实"
      )
  
      # new_sample = sample.insert_field_after_index('x', 1, '')
      # self.assertEqual('今天天气很好。', new_sample.get_text('x'))
      # self.assertEqual([0, 0, 0, 0, 0, 0, 0], new_sample.get_mask('x'))
  
      new_sample = sample.insert_field_after_index("x", 1, "确实")
      self.assertEqual("今天确实天气很好。", new_sample.get_text("x"))
      self.assertEqual(
          [0, 0, 2, 2, 0, 0, 0, 0, 0], new_sample.get_mask("x")
      )
  
      new_sample = sample.insert_field_after_index("x", 1, ["确", "实"])
      self.assertEqual("今天确实天气很好。", new_sample.get_text("x"))
      self.assertEqual(
          [0, 0, 2, 2, 0, 0, 0, 0, 0], new_sample.get_mask("x")
      )
  
imports: import unittest
  from textflint.input.component.sample.utcn_sample import *
label_desc: Use image node_id 16 for calling the TestUTCnSample obj's underlying member method code with example usage: obj.test_insert_field_after_index() without return types