code: public void setPingIntervalMsec(long pingIntervalMsec) {
          lock.lock();
          try {
              this.pingIntervalMsec = pingIntervalMsec;
              ListenableScheduledFuture<?> task = vPingTask;
              if (task != null)
                  task.cancel(false);
              setupPinging();
          } finally {
              lock.unlock();
          }
      }
docs: Sets the period between pings for an individual peer. Setting this lower means more accurate and timely ping
  times are available via {@link Peer#getLastPingTime()} but it increases load on the
  remote node. It defaults to {@link PeerGroup#DEFAULT_PING_INTERVAL_MSEC}.
  Setting the value to be smaller or equals 0 disables pinging entirely, although you can still request one yourself
  using {@link Peer#ping()}.