i've written bean class containing hashmultimap (from guava library). xml encode bean using jre's xmlencoder. using custom persistencedelegate i've written bean file. however, when attempt deserialize xml exception: java.lang.nosuchmethodexception: <unbound>=hashmultimap.put("pz1", "pz2") what doing wrong? // create bean somebean sb = new somebean(); // add data hashmultimap<string, string> statemap = hashmultimap.create(); statemap.put("pz1", "pz2"); statemap.put("pz3", "pz4"); sb.setstatemap(statemap); // encode xml fileoutputstream os = new fileoutputstream("myxmlfile.xml"); xmlencoder encoder = new xmlencoder(os); encoder.setpersistencedelegate(hashmultimap.class, new custompersistencedelegate()); encoder.writeobject(sb); // decode xml fileinputstream = new fileinputstream("myxmlfile.xml"); xmldecoder decoder = new xmldecoder(is); object deserializedobject ...