Swap some nullable annotations (#9696)

patches/api/0073-Add-PlayerArmorChangeEvent.patch

@@ -6,10 +6,10 @@ Subject: [PATCH] Add PlayerArmorChangeEvent
 
 diff --git a/src/main/java/com/destroystokyo/paper/event/player/PlayerArmorChangeEvent.java b/src/main/java/com/destroystokyo/paper/event/player/PlayerArmorChangeEvent.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..faea096dac02d339667c02a0011b6f8313fd8c12
+index 0000000000000000000000000000000000000000..57521010ff0574f1bbc96727948a6185fd37e9ee
 --- /dev/null
 +++ b/src/main/java/com/destroystokyo/paper/event/player/PlayerArmorChangeEvent.java
-@@ -0,0 +1,137 @@
+@@ -0,0 +1,139 @@
 +package com.destroystokyo.paper.event.player;
 +
 +import org.bukkit.Material;
@@ -22,6 +22,7 @@ index 0000000000000000000000000000000000000000..faea096dac02d339667c02a0011b6f83
 +import java.util.Collections;
 +import java.util.HashSet;
 +import java.util.Set;
++import org.jetbrains.annotations.ApiStatus;
 +import org.jetbrains.annotations.NotNull;
 +import org.jetbrains.annotations.Nullable;
 +
@@ -36,10 +37,11 @@ index 0000000000000000000000000000000000000000..faea096dac02d339667c02a0011b6f83
 +    private static final HandlerList HANDLERS = new HandlerList();
 +
 +    @NotNull private final SlotType slotType;
-+    @Nullable private final ItemStack oldItem;
-+    @Nullable private final ItemStack newItem;
++    @NotNull private final ItemStack oldItem;
++    @NotNull private final ItemStack newItem;
 +
-+    public PlayerArmorChangeEvent(@NotNull Player player, @NotNull SlotType slotType, @Nullable ItemStack oldItem, @Nullable ItemStack newItem) {
++    @ApiStatus.Internal
++    public PlayerArmorChangeEvent(@NotNull Player player, @NotNull SlotType slotType, @NotNull ItemStack oldItem, @NotNull ItemStack newItem) {
 +        super(player);
 +        this.slotType = slotType;
 +        this.oldItem = oldItem;
@@ -61,7 +63,7 @@ index 0000000000000000000000000000000000000000..faea096dac02d339667c02a0011b6f83
 +     *
 +     * @return old item
 +     */
-+    @Nullable
++    @NotNull
 +    public ItemStack getOldItem() {
 +        return this.oldItem;
 +    }
@@ -71,7 +73,7 @@ index 0000000000000000000000000000000000000000..faea096dac02d339667c02a0011b6f83
 +     *
 +     * @return new item
 +     */
-+    @Nullable
++    @NotNull
 +    public ItemStack getNewItem() {
 +        return this.newItem;
 +    }
@@ -137,10 +139,10 @@ index 0000000000000000000000000000000000000000..faea096dac02d339667c02a0011b6f83
 +        }
 +
 +        /**
-+         * Gets whether or not this material can be equipped to a slot
++         * Gets whether this material can be equipped to a slot
 +         *
 +         * @param material material to check
-+         * @return whether or not this material can be equipped
++         * @return whether this material can be equipped
 +         */
 +        public static boolean isEquipable(@NotNull Material material) {
 +            return getByMaterial(material) != null;