public boolean isCloned(Object o) {
        return index.containsKey(o);
    }
Returns true if the specified object has already been cloned
 by this cloner during this session.  Cloned objects are cached
 for later use, and it's sometimes convenient to know if some
 objects have already been cloned.

@param o the object to be tested
@return true if the object has been cloned, otherwise false
jme3-core/src/main/java/com/jme3/util/clone/Cloner.java