Changed Note equality check to not include group id

Author: RaphiMC

src/main/java/net/raphimc/noteblocklib/format/minecraft/ShiftedMinecraftInstrument.java

@@ -52,7 +52,7 @@ public int getOctavesShift() {
 
     @Override
     public ShiftedMinecraftInstrument copy() {
-        return new ShiftedMinecraftInstrument(this.instrument, this.octavesShift);
+        return this;
     }
 
     @Override

src/main/java/net/raphimc/noteblocklib/model/note/Note.java

@@ -40,6 +40,7 @@ public Note() {
 
     /**
      * @return The group ID of the note. Groups are used in events to determine which notes are affected by an event. -1 means that the note is not in any group.
+     * @implNote Not checked for in equals and hashCode, as it is only used for events and does not affect the sound of the note.
      */
     public int getGroupId() {
         return this.groupId;
@@ -48,6 +49,7 @@ public int getGroupId() {
     /**
      * @param groupId The group ID of the note. Groups are used in events to determine which notes are affected by an event. -1 means that the note is not in any group.
      * @return this
+     * @implNote Not checked for in equals and hashCode, as it is only used for events and does not affect the sound of the note.
      */
     public Note setGroupId(final int groupId) {
         this.groupId = groupId;
@@ -219,12 +221,12 @@ public Note copy() {
     public boolean equals(final Object o) {
         if (o == null || getClass() != o.getClass()) return false;
         final Note note = (Note) o;
-        return groupId == note.groupId && Float.compare(midiKey, note.midiKey) == 0 && Float.compare(volume, note.volume) == 0 && Float.compare(panning, note.panning) == 0 && Objects.equals(instrument, note.instrument);
+        return Float.compare(midiKey, note.midiKey) == 0 && Float.compare(volume, note.volume) == 0 && Float.compare(panning, note.panning) == 0 && Objects.equals(instrument, note.instrument);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(groupId, instrument, midiKey, volume, panning);
+        return Objects.hash(instrument, midiKey, volume, panning);
     }
 
 }

src/main/java/net/raphimc/noteblocklib/util/SongUtil.java

@@ -22,16 +22,13 @@
 import net.raphimc.noteblocklib.model.note.Note;
 import net.raphimc.noteblocklib.model.song.Song;
 
-import java.text.DecimalFormat;
 import java.util.Collections;
 import java.util.EnumSet;
 import java.util.IdentityHashMap;
 import java.util.Set;
 
 public class SongUtil {
 
-    private static final DecimalFormat DECIMAL_FORMAT = new DecimalFormat("#.##");
-
     /**
      * @param song The song
      * @return True if the song contains notes which are outside the vanilla Minecraft octave range.