UsbPlayerTest.quieterTest third Case

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

@@ -12,7 +12,7 @@ public class UsbPlayer implements Device {
     private Boolean isConnected;
     private Boolean isDefect;
     int Lautstaerke = 0;
-    int soundWas ;
+    int soundWas =-1;
 
     public USB_Stick USBDrive = new USB_Stick();
 
@@ -104,6 +104,7 @@ public class UsbPlayer implements Device {
     //**********search method*************
     @Override
     public void quieter() {
+        if(this.soundWas == -1){
             if (Lautstaerke > 0  ) {
                 Lautstaerke -= 1;
             } else {
@@ -111,6 +112,8 @@ public class UsbPlayer implements Device {
             }
         }
 
+    }
+
     @Override
     public void louder() {
         if (Lautstaerke < 100) {
@@ -193,7 +196,7 @@ public class UsbPlayer implements Device {
     public String unmute() {
 
         setLautstaerke(soundWas);
-        this.soundWas = 0;
+        this.soundWas = -1;
         return "unmuted";
     }
 

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

@@ -79,14 +79,25 @@ class UsbPlayerTest {
 
     static Stream<Arguments> quieterOptions() {
         USB_Stick USBDrive = new USB_Stick();
+        //first case
         UsbPlayer up1 = new UsbPlayer(USBDrive);
         up1.quieter();
+        //second case
         UsbPlayer up2 = new UsbPlayer(USBDrive);
         up2.setLautstaerke(10);
         up2.quieter();
+
+        //third case
+        UsbPlayer up3 = new UsbPlayer(USBDrive);
+        up3.setLautstaerke(10);
+        up3.mute();
+        up3.quieter();
+
         return Stream.of(
                 Arguments.of("Volume must stay 0 ", up1, 0),
-                Arguments.of("Volume must be 9 ", up2, 9)
+                Arguments.of("Volume must be 9 ", up2, 9),
+                Arguments.of("Volume is muted,no change can be made ", up3, 0)
+
         );
     }