* Initialize the map by reading in all the keys. This method blocks
* until the server has sent us the keys for this map.
*/
private void doInit() {
try {
ResponseMessage rm = channel.sendAndWait(new MapRequestMessage(getName()));
if (rm instanceof MapResponseMessage) {
MapResponseMessage mrm = (MapResponseMessage) rm;
backing.initialize(mrm.getVersion(), mrm.getKeys());
} else {
throw new IllegalStateException("Bad response to map request: " +