title: How to know if BLE device is connected currently
body: <p>Is there any method like device.isConnected() to know the present state of android BLE device . What I know is I need to implement some architecture like interface from GattclientCallBack class to know if device is connected,but I don't find any method like this. Also the method </p>
  
  <pre><code> mBluetoothGatt.getConnectionState(device);
  </code></pre>
  
  <p>returns int . So exactly how do I know if device is connected ?
  Thanks :)</p>