added new test case for play() & changed play() to show if playedStation is in regional or saved playlist

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

@@ -164,7 +164,10 @@ public class RadioPlayer implements Device {
 
     @Override
     public String play() {
-        return ("Radio is playing station: 0" + (savedPlaylist.indexOf(playedStation) + 1) + " " + this.playedStation);
+        if (regionPlaylist.contains(playedStation))
+            return ("Radio is playing station: 0" + (regionPlaylist.indexOf(playedStation) + 1) + " " + this.playedStation + " from regional playlist");
+        else
+            return ("Radio is playing station: 0" + (savedPlaylist.indexOf(playedStation) + 1) + " " + this.playedStation + " from saved playlist");
     }
 
     public String showStationInfo() {

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

@@ -185,9 +185,12 @@ class RadioPlayerTest {
 
     static Stream<Arguments> testPlayOptions() {
         RadioPlayer rp1 = new RadioPlayer();
+        RadioPlayer rp2 = new RadioPlayer();
+        rp2.changeRegion("BY");
 
         return Stream.of(
-                Arguments.of("Test for playing first station on saved playlist", rp1, "Radio is playing station: 01 YouFM")
+                Arguments.of("Test for playing first station on saved playlist", rp1, "Radio is playing station: 01 YouFM from saved playlist"),
+                Arguments.of("Test for playing first station on regional playlist", rp2, "Radio is playing station: 01 Antenne Bayern from regional playlist")
         );
     }