Add some testing

By: Erik Broes <erikbroes@grum.nl>

paper-api/src/main/java/org/bukkit/Effect.java

@@ -1,12 +1,16 @@
 package org.bukkit;
 
+import java.util.Map;
+
+import com.google.common.collect.Maps;
+
 /**
  * A list of effects that the server is able to send to players.
  */
 public enum Effect {
-    BOW_FIRE(1002),
-    CLICK1(1001),
     CLICK2(1000),
+    CLICK1(1001),
+    BOW_FIRE(1002),
     DOOR_TOGGLE(1003),
     EXTINGUISH(1004),
     RECORD_PLAY(1005),
@@ -20,12 +24,34 @@ public enum Effect {
     MOBSPAWNER_FLAMES(2004);
 
     private final int id;
+    private static final Map<Integer, Effect> BY_ID = Maps.newHashMap();
 
     Effect(int id) {
         this.id = id;
     }
 
+    /**
+     * Gets the ID for this effect.
+     *
+     * @return ID of this effect
+     */
     public int getId() {
         return this.id;
     }
+
+    /**
+     * Gets the Effect associated with the given ID.
+     *
+     * @param id ID of the Effect to return
+     * @return Effect with the given ID
+     */
+    public static Effect getById(int id) {
+        return BY_ID.get(id);
+    }
+
+    static {
+        for (Effect effect : values()) {
+            BY_ID.put(effect.id, effect);
+        }
+    }
 }