/** Handle a keep alive packet. */
 public void handleKeepAlive(Packet0KeepAlive par1Packet0KeepAlive) {
   if (par1Packet0KeepAlive.randomId == keepAliveRandomID) {
     int i = (int) (System.nanoTime() / 0xf4240L - keepAliveTimeSent);
     playerEntity.field_71138_i = (playerEntity.field_71138_i * 3 + i) / 4;
   }
 }