UsbPlayerTest.louderTest third Case

src/main/java/device/usbPlayer/UsbPlayer.java

@@ -116,10 +116,12 @@ public class UsbPlayer implements Device {
 
     @Override
     public void louder() {
-        if (Lautstaerke < 100) {
-            Lautstaerke += 1;
-        } else {
-            Lautstaerke = 100;
+        if(this.soundWas == -1) {
+            if (Lautstaerke < 100) {
+                Lautstaerke += 1;
+            } else {
+                Lautstaerke = 100;
+            }
         }
     }
 

src/test/java/device/usbPlayer/UsbPlayerTest.java

@@ -59,14 +59,25 @@ class UsbPlayerTest {
 
     static Stream<Arguments> louderOptions() {
         USB_Stick USBDrive = new USB_Stick();
+        //first case
         UsbPlayer up11 = new UsbPlayer(USBDrive);
         up11.louder();
+        //second case
         UsbPlayer up22 = new UsbPlayer(USBDrive);
         up22.setLautstaerke(100);
         up22.louder();
+        //third case
+        UsbPlayer up3 = new UsbPlayer(USBDrive);
+        up3.setLautstaerke(100);
+        up3.mute();
+        up3.louder();
+
+
+
         return Stream.of(
                 Arguments.of("Volume is : 1 ", up11, 1),
-                Arguments.of("Volume is : 100 ", up22, 100)
+                Arguments.of("Volume is : 100 ", up22, 100),
+                Arguments.of("Volume is muted,no change can be made ", up3, 0)
         );
     }