Cleanup and docs

Author: Doc94

paper-api/src/main/java/org/bukkit/MusicInstrument.java

@@ -5,7 +5,10 @@
 import io.papermc.paper.registry.RegistryKey;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.NoSuchElementException;
+import net.kyori.adventure.key.Key;
 import net.kyori.adventure.text.Component;
+import org.jetbrains.annotations.ApiStatus;
 import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
@@ -35,7 +38,7 @@ public abstract class MusicInstrument implements Keyed, net.kyori.adventure.tran
      * Returns a {@link MusicInstrument} by a {@link NamespacedKey}.
      *
      * @param namespacedKey the key
-     * @return the event or null
+     * @return the music instrument or null
      * @deprecated Use {@link Registry#get(NamespacedKey)} instead.
      */
     @Nullable
@@ -55,6 +58,14 @@ public static Collection<MusicInstrument> values() {
         return Collections.unmodifiableCollection(Lists.newArrayList(Registry.INSTRUMENT));
     }
 
+    /**
+     * Returns a {@link MusicInstrument} by a {@link String} key.
+     *
+     * @param key the key
+     * @return the music instrument
+     * @throws NoSuchElementException if there is no object with the given key
+     */
+    @ApiStatus.Internal
     private static MusicInstrument getInstrument(final String key) {
         return RegistryAccess.registryAccess().getRegistry(RegistryKey.INSTRUMENT).getOrThrow(NamespacedKey.minecraft(key));
     }
@@ -101,7 +112,7 @@ private static MusicInstrument getInstrument(final String key) {
      */
     @Deprecated(forRemoval = true, since = "1.20.5")
     @Override
-    public net.kyori.adventure.key.@org.jetbrains.annotations.NotNull Key key() {
+    public Key key() {
         return Keyed.super.key();
     }