Added documentation to Device.cloneState()

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/OutputDevice.java

@@ -13,5 +13,11 @@ public abstract class OutputDevice extends Device {
         super(kind, FlowType.OUTPUT);
     }
 
+    /**
+     * Creates a State<?> object initialized to point at this device and with values copied from
+     * this device's state
+     *
+     * @return a new State<?> object
+     */
     public abstract State<? extends OutputDevice> cloneState();
 }