Method-Name "quiter" -> "quieter". CDPlayer and CDPlayerTest classes added to project.

src/main/java/device/CDPlayer.java

@@ -0,0 +1,48 @@
+package device;
+
+public class CDPlayer implements Device {
+    @Override
+    public void louder() {
+
+    }
+
+    @Override
+    public void quieter() {
+
+    }
+
+    @Override
+    public int getVolume() {
+        return 0;
+    }
+
+    @Override
+    public void next() {
+
+    }
+
+    @Override
+    public void prev() {
+
+    }
+
+    @Override
+    public String getInfoText() {
+        return null;
+    }
+
+    @Override
+    public String[] getOptions() {
+        return new String[0];
+    }
+
+    @Override
+    public void chooseOption(String opt) {
+
+    }
+
+    @Override
+    public String play() {
+        return null;
+    }
+}

src/main/java/device/Device.java

@@ -3,7 +3,7 @@ package device;
 public interface Device {
 
 	void louder();
-	void quiter();
+	void quieter();
 	int getVolume();
 	void next();
 	void prev();

src/main/java/device/RadioPlayer.java

@@ -7,7 +7,7 @@ public class RadioPlayer implements Device {
     }
 
     @Override
-    public void quiter() {
+    public void quieter() {
 
     }
 

src/main/java/device/UsbPlayer.java

@@ -8,7 +8,7 @@ public class UsbPlayer implements Device{
     }
 
     @Override
-    public void quiter() {
+    public void quieter() {
 
     }
 

src/test/java/device/CDPlayerTest.java

@@ -0,0 +1,44 @@
+package device;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class CDPlayerTest {
+
+    @Test
+    void louder() {
+    }
+
+    @Test
+    void quieter() {
+    }
+
+    @Test
+    void getVolume() {
+    }
+
+    @Test
+    void next() {
+    }
+
+    @Test
+    void prev() {
+    }
+
+    @Test
+    void getInfoText() {
+    }
+
+    @Test
+    void getOptions() {
+    }
+
+    @Test
+    void chooseOption() {
+    }
+
+    @Test
+    void play() {
+    }
+}