Added topic restoration after music player is shutdown

src/main/java/netneutrality/music/MusicManager.java

@@ -34,6 +34,7 @@ public class MusicManager {
     private final static Map<String, MusicManager> managers = new ConcurrentHashMap<>();
     private long guildId;
     private boolean isPlaying = false;
+    private String topic;
 
     private MusicManager(Guild guild) {
 
@@ -93,7 +94,7 @@ public class MusicManager {
 
     public synchronized void stopMusic() {
         if (scheduler.getTextChannel() != null)
-            scheduler.getTextChannel().getManager().setTopic("").queue();
+            scheduler.getTextChannel().getManager().setTopic(scheduler.topic).queue();
 
         player.destroy();
     }

src/main/java/netneutrality/music/TrackScheduler.java

@@ -21,6 +21,7 @@ public class TrackScheduler extends AudioEventAdapter {
     private final AudioPlayer player;
     private TextChannel channel;
     public final BlockingQueue<AudioTrack> queue;
+    public String topic;
 
     public TrackScheduler(AudioPlayer player) {
         this.player = player;
@@ -40,6 +41,7 @@ public class TrackScheduler extends AudioEventAdapter {
 
     public void setTextChannel(TextChannel channel) {
         this.channel = channel;
+        topic = channel.getTopic();
     }
 
     public TextChannel getTextChannel() {
@@ -56,7 +58,7 @@ public class TrackScheduler extends AudioEventAdapter {
         if (track != null)
             channel.getManager().setTopic(":speaker: Now playing : " + track.getInfo().title).queue();
         else
-            channel.getManager().setTopic("").queue();
+            channel.getManager().setTopic(topic).queue();
         player.startTrack(track, false);
     }