@Override
      public boolean isDone() {
        boolean rv = true;
        for (Operation op : ops) {
          rv &= op.getState() == OperationState.COMPLETE;
        }
        return rv || isCancelled();
      }
Flush all caches from all servers with a delay of application.

@param delay the period of time to delay, in seconds
@return whether or not the operation was accepted
@throws IllegalStateException in the rare circumstance where queue is too
          full to accept any more requests
src/main/java/net/spy/memcached/MemcachedClient.java