added second test case for changeOrderInSavedPlaylist() & and added productive code

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

@@ -213,8 +213,14 @@ public class RadioPlayer implements Device {
 
     public String changeOrderInSavedPlaylist(int nr) {
         String station = playedStation;
+        if((nr-1) > savedPlaylist.size()) {
             savedPlaylist.remove(playedStation);
-        savedPlaylist.add(nr-1,station);
+            savedPlaylist.add(savedPlaylist.size(),station);
             return"Station " + playedStation + " is now on place 0" + nr + "in saved playlist";
+        } else {
+            savedPlaylist.remove(playedStation);
+            savedPlaylist.add(nr - 1, station);
+            return "Station " + playedStation + " is now on place 0" + (savedPlaylist.size()+1) + "in saved playlist";
+        }
     }
 }

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

@@ -277,9 +277,12 @@ class RadioPlayerTest {
         RadioPlayer rp = new RadioPlayer();
         rp.next();
         rp.changeOrderInSavedPlaylist(1);
+        RadioPlayer rp1 = new RadioPlayer();
+        rp1.changeOrderInSavedPlaylist(5);
 
         return Stream.of(
-                Arguments.of("Test for change order in saved playlist with nr isn`t than playlist size", rp, 0, "Teddy")
+                Arguments.of("Test for change order in saved playlist with nr isn`t bigger than playlist size", rp, 0, "Teddy"),
+                Arguments.of("Test for change order in saved playlist with nr is than bigger playlist size but at the end of playlist", rp1, 2, "YouFM")
         );
     }
 }