Add player elytra boost API

Spigot-API-Patches/0230-Player-elytra-boost-API.patch

@@ -0,0 +1,30 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Trigary <trigary0@gmail.com>
+Date: Tue, 14 Apr 2020 12:06:14 +0200
+Subject: [PATCH] Player elytra boost API
+
+
+diff --git a/src/main/java/org/bukkit/entity/Player.java b/src/main/java/org/bukkit/entity/Player.java
+index 991f757a89d2e917186bb152a2f92bad8b6c2897..16bdb4b717368d121e84121f85bbf3de5fb642f1 100644
+--- a/src/main/java/org/bukkit/entity/Player.java
++++ b/src/main/java/org/bukkit/entity/Player.java
+@@ -1777,6 +1777,19 @@ public interface Player extends HumanEntity, Conversable, OfflinePlayer, PluginM
+      */
+     @NotNull
+     <T> T getClientOption(@NotNull ClientOption<T> option);
++
++    /**
++     * Boost a Player that's {@link #isGliding()} using a {@link Firework}.
++     * If the creation of the entity is cancelled, no boosting is done.
++     * This method does not fire {@link com.destroystokyo.paper.event.player.PlayerElytraBoostEvent}.
++     *
++     * @param firework The {@link Material#FIREWORK_ROCKET} to boost the player with
++     * @return The {@link Firework} boosting the Player or null if the spawning of the entity was cancelled
++     * @throws IllegalArgumentException if {@link #isGliding()} is false
++     * or if the {@code firework} isn't a {@link Material#FIREWORK_ROCKET}
++     */
++    @Nullable
++    Firework boostElytra(@NotNull ItemStack firework);
+     // Paper end
+ 
+     // Spigot start