SPIGOT-2540: Add nullability annotations to entire Bukkit API

By: Darkyenus <darkyenus@gmail.com>

paper-api/src/main/java/org/bukkit/permissions/PermissionAttachmentInfo.java

@@ -1,5 +1,8 @@
 package org.bukkit.permissions;
 
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
 /**
  * Holds information on a permission and which {@link PermissionAttachment}
  * provides it
@@ -10,11 +13,11 @@ public class PermissionAttachmentInfo {
     private final PermissionAttachment attachment;
     private final boolean value;
 
-    public PermissionAttachmentInfo(Permissible permissible, String permission, PermissionAttachment attachment, boolean value) {
+    public PermissionAttachmentInfo(@NotNull Permissible permissible, @NotNull String permission, @Nullable PermissionAttachment attachment, boolean value) {
         if (permissible == null) {
             throw new IllegalArgumentException("Permissible may not be null");
         } else if (permission == null) {
-            throw new IllegalArgumentException("Permissions may not be null");
+            throw new IllegalArgumentException("Permission may not be null");
         }
 
         this.permissible = permissible;
@@ -28,6 +31,7 @@ public class PermissionAttachmentInfo {
      *
      * @return Permissible this permission is for
      */
+    @NotNull
     public Permissible getPermissible() {
         return permissible;
     }
@@ -37,6 +41,7 @@ public class PermissionAttachmentInfo {
      *
      * @return Name of the permission
      */
+    @NotNull
     public String getPermission() {
         return permission;
     }
@@ -47,6 +52,7 @@ public class PermissionAttachmentInfo {
      *
      * @return Attachment
      */
+    @Nullable
     public PermissionAttachment getAttachment() {
         return attachment;
     }