Mark PlayerMoveEvent#setTo as NotNull

Spigot-API-Patches/0051-Fix-upstream-javadoc-warnings-and-errors.patch

@@ -1,4 +1,4 @@
-From 0073358c87abe5e1b89363c51a06ff694a01f965 Mon Sep 17 00:00:00 2001
+From cc46bf75294e7b9ce639b3d6bde64193799859d9 Mon Sep 17 00:00:00 2001
 From: Zach Brown <zach.brown@destroystokyo.com>
 Date: Sat, 10 Jun 2017 16:59:40 -0500
 Subject: [PATCH] Fix upstream javadoc warnings and errors
@@ -286,6 +286,19 @@ index 8d4c70031..b493173e2 100644
       */
      public PlayerLoginEvent(@NotNull final Player player, @NotNull String hostname, @NotNull final InetAddress address, @NotNull final Result result, @NotNull final String message, @NotNull final InetAddress realAddress) { // Spigot
          this(player, hostname, address, realAddress); // Spigot
+diff --git a/src/main/java/org/bukkit/event/player/PlayerMoveEvent.java b/src/main/java/org/bukkit/event/player/PlayerMoveEvent.java
+index 8b9018451..374fe3644 100644
+--- a/src/main/java/org/bukkit/event/player/PlayerMoveEvent.java
++++ b/src/main/java/org/bukkit/event/player/PlayerMoveEvent.java
+@@ -76,7 +76,7 @@ public class PlayerMoveEvent extends PlayerEvent implements Cancellable {
+      *
+      * @return Location the player moved to
+      */
+-    @Nullable
++    @NotNull // Paper
+     public Location getTo() {
+         return to;
+     }
 diff --git a/src/main/java/org/bukkit/inventory/ItemFactory.java b/src/main/java/org/bukkit/inventory/ItemFactory.java
 index 07d2b4cfe..cbcbe8c8a 100644
 --- a/src/main/java/org/bukkit/inventory/ItemFactory.java