String message = NbtException.getErrorString(errSsn, errorCode);
        assertTrue(message.contains(description));
    }

    @Test
    @DisplayName("getErrorString for unknown error class")
    void testUnknownErrorClass() {
        int unknownClass = 1234;
        String expected = "unknown error class: 1234";
        assertEquals(expected, NbtException.getErrorString(unknownClass, 0));
    }

    @Test