@Test
    public void testAlphaUpper() {
        assertEquals("A", AutoPageNumberUtils.asAlphaNumeric(1));
        assertEquals("Z", AutoPageNumberUtils.asAlphaNumeric(26));
        assertEquals("AA", AutoPageNumberUtils.asAlphaNumeric(27));
        assertEquals("ZZ", AutoPageNumberUtils.asAlphaNumeric(52));
        assertEquals("AAA", AutoPageNumberUtils.asAlphaNumeric(53));
        assertEquals("ZZZ", AutoPageNumberUtils.asAlphaNumeric(78));
    }
Check upper-case alpha-numeric numbers are generated based on the
input page number.
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-apple-module/src/test/java/org/apache/tika/parser/iwork/AutoPageNumberUtilsTest.java