public void print() {
        if (newLen > 0) {
            System.out.print("New List: ");
            for (int i = 0; i < newLen; i++) {
                if (i == newLen - 1) {
                    System.out.println(newList[i]);
                } else {
                    System.out.print(newList[i] + ", ");
                }
            }
        }
        if (oldLen > 0) {
            System.out.print("Old List: ");
            for (int i = 0; i < oldLen; i++) {
                if (i == oldLen - 1) {
                    System.out.println(oldList[i]);
                } else {
                    System.out.print(oldList[i] + ", ");
                }
            }
        }
    }
Prints the contents of the lists.
jme3-core/src/main/java/com/jme3/renderer/IDList.java