Made deepCopy public (#1091)

* Made deepCopy public

* since 2.8.2

gson/src/main/java/com/google/gson/JsonArray.java

@@ -44,8 +44,12 @@ public final class JsonArray extends JsonElement implements Iterable<JsonElement
     elements = new ArrayList<JsonElement>(capacity);
   }
 
+  /**
+   * Creates a deep copy of this element and all its children
+   * @since 2.8.2
+   */
   @Override
-  JsonArray deepCopy() {
+  public JsonArray deepCopy() {
     if (!elements.isEmpty()) {
       JsonArray result = new JsonArray(elements.size());
       for (JsonElement element : elements) {

gson/src/main/java/com/google/gson/JsonElement.java

@@ -34,8 +34,9 @@ public abstract class JsonElement {
   /**
    * Returns a deep copy of this element. Immutable elements like primitives
    * and nulls are not copied.
+   * @since 2.8.2
    */
-  abstract JsonElement deepCopy();
+  public abstract JsonElement deepCopy();
 
   /**
    * provides check for verifying if this element is an array or not.

gson/src/main/java/com/google/gson/JsonNull.java

@@ -40,8 +40,12 @@ public final class JsonNull extends JsonElement {
     // Do nothing
   }
 
+  /**
+   * Returns the same instance since it is an immutable value
+   * @since 2.8.2
+   */
   @Override
-  JsonNull deepCopy() {
+  public JsonNull deepCopy() {
     return INSTANCE;
   }
 

gson/src/main/java/com/google/gson/JsonObject.java

@@ -33,8 +33,12 @@ public final class JsonObject extends JsonElement {
   private final LinkedTreeMap<String, JsonElement> members =
       new LinkedTreeMap<String, JsonElement>();
 
+  /**
+   * Creates a deep copy of this element and all its children
+   * @since 2.8.2
+   */
   @Override
-  JsonObject deepCopy() {
+  public JsonObject deepCopy() {
     JsonObject result = new JsonObject();
     for (Map.Entry<String, JsonElement> entry : members.entrySet()) {
       result.add(entry.getKey(), entry.getValue().deepCopy());

gson/src/main/java/com/google/gson/JsonPrimitive.java

@@ -85,8 +85,12 @@ public final class JsonPrimitive extends JsonElement {
     setValue(primitive);
   }
 
+  /**
+   * Returns the same value as primitives are immutable.
+   * @since 2.8.2
+   */
   @Override
-  JsonPrimitive deepCopy() {
+  public JsonPrimitive deepCopy() {
     return this;
   }