code: public Serializable generate(SessionImplementor session, Object object)
              throws HibernateException {
          UUID uuid = UUID.randomUUID();
          StringBuilder sb = new StringBuilder();
  
          sb.append(Long.toHexString(uuid.getMostSignificantBits()));
          sb.append(Long.toHexString(uuid.getLeastSignificantBits()));
  
          while (sb.length() < 32) {
              sb.append('0');
          }
  
          return sb.toString();
      }
docs: -------------------------------------------------------------