code: public long getSessionId() {
          long sessionId = 0;
          try {
              ZooKeeper zk = zooKeeper.getZooKeeper();
              if (zk != null) {
                  sessionId = zk.getSessionId();
              }
          } catch (Exception e) {
              // Ignore the exception
          }
          return sessionId;
      }
docs: Return the current session id