@Override
      public boolean cancel(boolean ign) {
        boolean rv = false;
        for (Operation op : ops) {
          op.cancel();
          rv |= op.getState() == OperationState.WRITE_QUEUED;
        }
        notifyListeners();
        return rv;
      }
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