changed from getLautstaerke() to getVolume() like it is defined in device interface

src/main/java/device/radioPlayer/RadioPlayer.java

@@ -64,10 +64,6 @@ public class RadioPlayer implements Device {
         Lautstaerke = lautstaerke;
     }
 
-    public int getLautstaerke() {
-        return Lautstaerke;
-    }
-
     public void changeRegion(String region){
         switch (region) {
             case "BY":
@@ -117,7 +113,7 @@ public class RadioPlayer implements Device {
     }
     @Override
     public int getVolume() {
-        return 0;
+        return Lautstaerke;
     }
 
     @Override

src/test/java/device/radioPlayer/RadioPlayerTest.java

@@ -19,7 +19,7 @@ class RadioPlayerTest {
     @ParameterizedTest
     @MethodSource("quieterLouderOptions")
     void quieterLouderTest(String testName, RadioPlayer testRp, int expectedResult) {
-        int volume = testRp.getLautstaerke();
+        int volume = testRp.getVolume();
         assertThat(volume).describedAs(testName).isEqualTo(expectedResult);
     }
 
@@ -67,12 +67,6 @@ class RadioPlayerTest {
     }
 
 
-/*
-    @Test
-    void getVolume() {
-    }
-*/
-
     @ParameterizedTest
     @MethodSource("prevNextOptions")
     void prevNextTest(String testName, RadioPlayer testRp, String expectedResult) {