iiop-openjdk/src/main/java/org/wildfly/iiop/openjdk/rmi/ContainerAnalysis.java
protected String toHexString(long l) {
        String s = Long.toHexString(l).toUpperCase(Locale.ENGLISH);

        if (s.length() < 16)
            return "0000000000000000".substring(0, 16 - s.length()) + s;
        else
            return s;
    }
protected String toHexString(long l) {
        String s = Long.toHexString(l).toUpperCase(Locale.ENGLISH);

        if (s.length() < 16)
            return "0000000000000000".substring(0, 16 - s.length()) + s;
        else
            return s;
    }
Convert a long to a 16-digit hex string.