def METHOD_NAME(self) -> None:
    """Test case to check behaviour of convert_string_to_bool method."""
    self.assertTrue(
        payload_validator.convert_string_to_bool('true'))
    self.assertFalse(
        payload_validator.convert_string_to_bool('false'))
    self.assertEqual(
        payload_validator.convert_string_to_bool('any_other_value'),
        'any_other_value'
    )