Alpaca Market Data API stops feeding data after several hours #169

Hello, I have been using the Alpaca Client for quite some time now and set it up to work with the MarketDataApi so it can receive real-time data about the stock market by subscribing the specific stock and adding StockMarketDataListener which to receive the data with the onData event. The only problem I had so far is that after approximately 4 hours of receiving data it stops feeding anything, until i restart it. My question is am I missing something that needs to be added as a parameter or is there a mechanism to send heart-beat ping to let alpaca server know to keep the connection alive. Also I never kept the connection working for two consecutive days so I do not know if it continues to not receive data even on the next day after it stops.