text: import unittest
  from typing import Any, List
  
  from hstest.check_result import CheckResult
  from hstest.stage_test import StageTest
  from hstest.test_case import TestCase
  
  
  class TestCustomChecker(StageTest):
      def generate(self) -> List[TestCase]:
          return [
              TestCase(
                  attach='4\n-in\n123\nout\n234\n',
                  args=['-in', '123', 'out', '234'],
                  check_function=self.custom_check
              ),
              TestCase(
                  attach='5\n-in\n435\nout\n567\n789\n',
                  args=['-in', '435', 'out', '567', '789']
              ),
  
          ]
  
      def custom_check(self, reply: str, attach: Any) -> CheckResult:
          return CheckResult(reply == attach, '')
  
  
  class Test(unittest.TestCase):
      def test(self):
          status, feedback = TestCustomChecker(
              'tests.outcomes.test_custom_checker.program'
          ).run_tests()
  
          self.assertIn("Fatal error in test #2, please send the report "
                        "to support@hyperskill.org", feedback)
          self.assertIn("FatalErrorException: Can't "
                        "check result: override \"check\" method", feedback)
          self.assertEqual(status, -1)
  