added AssertJ test for "maximale Lautstärke"

src/test/java/device/RadioPlayerTest.java

@@ -1,35 +1,26 @@
 package device;
 
-import org.junit.Before;
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.junit.jupiter.api.Assertions.*;
 
 class RadioPlayerTest {
 
     RadioPlayer rp = new RadioPlayer();
 
-    @Before
-    void setup()
-    {
-        rp.setLautstaerke(0);
-    }
+
     @Test
     void louder() {
+        rp.setLautstaerke(0);
         rp.louder();
         assertThat(rp.getLautstaerke()).isEqualTo(1);
     }
 
-    @Before
-    void setup1()
-    {
-        rp.setLautstaerke(100);
-    }
-
     @Test
-    void loudermax() {
-
+    void louderMax() {
+        rp.setLautstaerke(100);
+        rp.louder();
+        assertThat(rp.getLautstaerke()).isEqualTo(100);
     }
 /*
     @Test