public static void checkMrzCheckDigit(String mrz) {
        final char checkDigit = calculateCheckDigit(mrz.substring(0, mrz.length() - 1));
        if (checkDigit != mrz.charAt(mrz.length() - 1)) {
            throw new VerificationException(String.format(
                    "The check digit of MRZ is not correct [%c != %c]",
                    checkDigit, mrz.charAt(mrz.length() - 1)));
        }
    }
@Test
    public void checkMrzCheckDigit() {
        MrzUtils.checkMrzCheckDigit("PPPPPPPPPPPPPPPPPPPPPPPPPPPPPP");
        MrzUtils.checkMrzCheckDigit("PPPPPPPPP");
        assertThrows(VerificationException.class, () -> {
            MrzUtils.checkMrzCheckDigit("PPPPPPPPPPPPPPPPPPPPPPPPPPPPPP");
        });
    }