public Class[] getMessageTypes() {
        if( messageTypes == null ) {
            messageTypes = methods.keySet().toArray(new Class[methods.size()]);
        }
        return messageTypes;
    }
Returns the array of messages known to be handled by this message
 delegator.
jme3-networking/src/main/java/com/jme3/network/util/AbstractMessageDelegator.java