TransformedMap is Serializable but its superclass doesn't define an accessible void constructor

public void testSerialisation() throws Exception {
    TransformedMap<String, String, String, String> map = TransformedMap.decorate(
            new HashMap<String, String>(),  NOPTransformer.<String> getInstance(), NOPTransformer.<String> getInstance());
    ByteArrayOutputStream bytes = new ByteArrayOutputStream();
    ObjectOutputStream out = new ObjectOutputStream(bytes);
    out.writeObject(map); // fails with java.io.InvalidClassException: org.apache.commons.collections.splitmap.TransformedMap; no valid constructor
    out.close();
}