String decoded = new String(BaseEncoding.base64().decode(encoded), StandardCharsets.UTF_8);

        assertEquals(specialString, decoded);
    }

    @Test
    public void test_empty_string_base64_encoding() {
        // Test that empty strings are properly encoded/decoded
        String emptyString = "";
        String encoded = BaseEncoding.base64().encode(emptyString.getBytes(StandardCharsets.UTF_8));