Adds some documentation

src/main/java/net/minestom/server/item/firework/FireworkEffect.java

@@ -1,9 +1,11 @@
 package net.minestom.server.item.firework;
 
 import net.minestom.server.chat.ChatColor;
-import net.minestom.server.item.metadata.FireworkMeta;
+import org.jetbrains.annotations.NotNull;
 import org.jglrxavpok.hephaistos.nbt.NBTCompound;
 
+import java.util.Objects;
+
 public class FireworkEffect {
 
     private final boolean flicker;
@@ -18,8 +20,8 @@ public class FireworkEffect {
      * @param flicker   {@code true} if this explosion has the Twinkle effect (glowstone dust), otherwise {@code false}.
      * @param trail     {@code true} if this explosion hsa the Trail effect (diamond), otherwise {@code false}.
      * @param type      The shape of this firework's explosion.
-     * @param color
-     * @param fadeColor
+     * @param color     The primary color of this firework effect.
+     * @param fadeColor The secondary color of this firework effect.
      */
     public FireworkEffect(boolean flicker, boolean trail, FireworkEffectType type, ChatColor color, ChatColor fadeColor) {
         this.flicker = flicker;
@@ -29,7 +31,13 @@ public class FireworkEffect {
         this.fadeColor = fadeColor;
     }
 
-    public static FireworkEffect fromCompound(NBTCompound compound) {
+    /**
+     * Retrieves a firework effect from the given {@code compound}.
+     *
+     * @param compound The NBT connection, which should be a fireworks effect.
+     * @return A new created firework effect.
+     */
+    public static FireworkEffect fromCompound(@NotNull NBTCompound compound) {
 
         ChatColor primaryColor = null;
         ChatColor secondaryColor = null;
@@ -58,10 +66,20 @@ public class FireworkEffect {
                 secondaryColor);
     }
 
+    /**
+     * Whether the firework has a flicker effect.
+     *
+     * @return {@code 1} if this explosion has the flicker effect, otherwise {@code 0}.
+     */
     public byte getFlicker() {
         return (byte) (this.flicker ? 1 : 0);
     }
 
+    /**
+     * Whether the firework has a trail effect.
+     *
+     * @return {@code 1} if this explosion has the trail effect, otherwise {@code 0};
+     */
     public byte getTrail() {
         return (byte) (this.trail ? 1 : 0);
     }
@@ -123,4 +141,26 @@ public class FireworkEffect {
         return explosionCompound;
     }
 
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        FireworkEffect that = (FireworkEffect) o;
+        return flicker == that.flicker &&
+                trail == that.trail &&
+                type == that.type &&
+                Objects.equals(color, that.color) &&
+                Objects.equals(fadeColor, that.fadeColor);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public int hashCode() {
+        return Objects.hash(flicker, trail, type, color, fadeColor);
+    }
 }

src/main/java/net/minestom/server/item/firework/FireworkEffectType.java

@@ -29,10 +29,21 @@ public enum FireworkEffectType {
         this.type = type;
     }
 
+    /**
+     * Retrieves a {@link FireworkEffectType} by the given {@code id}.
+     *
+     * @param id The identifier of the firework effect type.
+     * @return A firework effect type or {@code null}.
+     */
     public static FireworkEffectType byId(byte id) {
         return BY_ID.get(id);
     }
 
+    /**
+     * Retrieves the type of the firework effect.
+     *
+     * @return The type of the firework effect as a byte.
+     */
     public byte getType() {
         return type;
     }

src/main/java/net/minestom/server/item/metadata/FireworkMeta.java

@@ -18,38 +18,82 @@ public class FireworkMeta extends ItemMeta {
     private List<FireworkEffect> effects = new ArrayList<>();
     private byte flightDuration;
 
+    /**
+     * Adds a firework effect to this firework.
+     *
+     * @param effect The firework effect to be added.
+     */
     public void addFireworkEffect(FireworkEffect effect) {
         this.effects.add(effect);
     }
 
+    /**
+     * Adds an array of firework effects to this firework.
+     *
+     * @param effects An array of firework effects to be added.
+     */
     public void addFireworkEffects(FireworkEffect... effects) {
         this.effects.addAll(Arrays.asList(effects));
     }
 
+    /**
+     * Removes a firework effect from this firework.
+     *
+     * @param index The index of the firework effect to be removed.
+     * @throws IndexOutOfBoundsException If index {@literal < 0 or index >} {@link #getEffectSize()}
+     */
     public void removeFireworkEffect(int index) throws IndexOutOfBoundsException {
         this.effects.remove(index);
     }
 
+    /**
+     * Removes a firework effects from this firework.
+     *
+     * @param effect The effect to be removed.
+     */
     public void removeFireworkEffect(FireworkEffect effect) {
         this.effects.remove(effect);
     }
 
+    /**
+     * Retrieves a collection with all effects in this firework.
+     *
+     * @return A collection with all effects in this firework.
+     */
     public List<FireworkEffect> getEffects() {
         return effects;
     }
 
+    /**
+     * Retrieves the size of effects in this firework.
+     *
+     * @return The size of the effects.
+     */
     public int getEffectSize() {
         return this.effects.size();
     }
 
+    /**
+     * Removes all effects from this firework.
+     */
     public void clearEffects() {
         this.effects.clear();
     }
 
+    /**
+     * Whether this firework has any effects.
+     *
+     * @return {@code true} if this firework has any effects, otherwise {@code false}.
+     */
     public boolean hasEffects() {
         return this.effects.isEmpty();
     }
 
+    /**
+     * Changes the flight duration of this firework.
+     *
+     * @param flightDuration The new flight duration for this firework.
+     */
     public void setFlightDuration(byte flightDuration) {
         this.flightDuration = flightDuration;
     }

src/main/java/net/minestom/server/item/metadata/ItemMeta.java

@@ -44,6 +44,9 @@ public abstract class ItemMeta implements PublicCloneable<ItemMeta> {
      */
     public abstract void write(@NotNull NBTCompound compound);
 
+    /**
+     * {@inheritDoc}
+     */
     @NotNull
     @Override
     public ItemMeta clone() {

src/main/java/net/minestom/server/utils/clone/PublicCloneable.java

@@ -9,6 +9,11 @@ import org.jetbrains.annotations.NotNull;
  */
 public interface PublicCloneable<T> extends Cloneable {
 
+    /**
+     * Creates and returns a copy of this object.
+     *
+     * @return A clone of this instance.
+     */
     @NotNull
     T clone();
 }