makes fields private

Java/src/main/java/com/gildedrose/item/AgedBrie.java

@@ -2,7 +2,7 @@ package com.gildedrose.item;
 
 public class AgedBrie implements CustomisedItem {
 
-    public Item item;
+    private final Item item;
 
     public AgedBrie(Item item) {
         this.item = item;

Java/src/main/java/com/gildedrose/item/BackstagePassesItem.java

@@ -2,7 +2,7 @@ package com.gildedrose.item;
 
 public class BackstagePassesItem implements CustomisedItem {
 
-    public Item item;
+    private final Item item;
 
     public BackstagePassesItem(Item item) {
         this.item = item;

Java/src/main/java/com/gildedrose/item/CustomisedItemFactory.java

@@ -9,7 +9,7 @@ public class CustomisedItemFactory {
 
     public CustomisedItem customiseItem(Item item) {
         if (item.name.equals(SULFURAS)) {
-            return new Sulfuras(item);
+            return new Sulfuras();
         } else if (item.name.equals(BRIE)) {
             return new AgedBrie(item);
         } else if (item.name.equals(BACKSTAGE_PASSES_ITEM)) {

Java/src/main/java/com/gildedrose/item/StandardItem.java

@@ -2,7 +2,7 @@ package com.gildedrose.item;
 
 public class StandardItem implements CustomisedItem {
 
-    public Item item;
+    private final Item item;
 
     public StandardItem(Item item) {
         this.item = item;

Java/src/main/java/com/gildedrose/item/Sulfuras.java

@@ -2,11 +2,6 @@ package com.gildedrose.item;
 
 public class Sulfuras implements CustomisedItem {
 
-    public Item item;
-
-    public Sulfuras(Item item) {
-    }
-
     public void updateState() {
     }
 }