@Test
public void testDecode() {

    // przypadki testowe
    Object[][] testCases = {
        {"abc", new StringHolder("abc")},
        {"", new StringHolder("")},
        {null, new StringHolder(null)}
    };
    // wykonanie testow
    for (Object[] testCase : testCases) {
        String text = (String) testCase[0];
        StringHolder expectedHolder = (StringHolder) testCase[1];
        StringHolder holder = type.decode(text);
        assertEquals(expectedHolder.getValue(), holder.getValue());
    }
}