code: public String getID() {
          byte[] genBytes = new byte[_byteArraySize];
          synchronized(_random) {
              _random.nextBytes(genBytes);
          }
          String id = convertSessionIdBytesToSessionId(genBytes, _sessionIDLength);
          if (logger.isLoggable(Level.FINE)) {
              logger.logp(Level.FINE, methodClassName, "getSessionID", "sessionID=" + id);
          }
          return id;
      }
docs: ----------------------------------------