@Override
          public void receivedStatus(OperationStatus status) {
            for (String s : status.getMessage().split(" ")) {
              rv.put(s, s);
            }
          }
Flush all caches from all servers immediately.

@return whether or not the operation was performed
@throws IllegalStateException in the rare circumstance where queue is too
          full to accept any more requests
src/main/java/net/spy/memcached/MemcachedClient.java