Enable subclasses to be serializable

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/collections/trunk@131622 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/collections/map/AbstractMapDecorator.java

@@ -33,7 +33,7 @@ import java.util.Set;
  * But, you might want that loophole, so this class is kept simple.
  *
  * @since Commons Collections 3.0
- * @version $Revision: 1.4 $ $Date: 2004/02/18 01:13:19 $
+ * @version $Revision: 1.5 $ $Date: 2004/04/02 21:02:54 $
  * 
  * @author Daniel Rall
  * @author Stephen Colebourne
@@ -41,7 +41,15 @@ import java.util.Set;
 public abstract class AbstractMapDecorator implements Map {
 
     /** The map to decorate */
-    protected final Map map;
+    protected transient Map map;
+
+    /**
+     * Constructor only used in deserialization, do not use otherwise.
+     * @since Commons Collections 3.1
+     */
+    protected AbstractMapDecorator() {
+        super();
+    }
 
     /**
      * Constructor that wraps (not copies).