SPIGOT-2540: Add nullability annotations to entire Bukkit API

By: Darkyenus <darkyenus@gmail.com>

paper-api/src/main/java/org/bukkit/configuration/ConfigurationOptions.java

@@ -1,5 +1,7 @@
 package org.bukkit.configuration;
 
+import org.jetbrains.annotations.NotNull;
+
 /**
  * Various settings for controlling the input and output of a {@link
  * Configuration}
@@ -9,7 +11,7 @@ public class ConfigurationOptions {
     private boolean copyDefaults = false;
     private final Configuration configuration;
 
-    protected ConfigurationOptions(Configuration configuration) {
+    protected ConfigurationOptions(@NotNull Configuration configuration) {
         this.configuration = configuration;
     }
 
@@ -18,6 +20,7 @@ public class ConfigurationOptions {
      *
      * @return Parent configuration
      */
+    @NotNull
     public Configuration configuration() {
         return configuration;
     }
@@ -45,6 +48,7 @@ public class ConfigurationOptions {
      * @param value Path separator
      * @return This object, for chaining
      */
+    @NotNull
     public ConfigurationOptions pathSeparator(char value) {
         this.pathSeparator = value;
         return this;
@@ -83,6 +87,7 @@ public class ConfigurationOptions {
      * @param value Whether or not defaults are directly copied
      * @return This object, for chaining
      */
+    @NotNull
     public ConfigurationOptions copyDefaults(boolean value) {
         this.copyDefaults = value;
         return this;