private void InternalFlush(INextFilter nextFilter, IoSession session, IoBuffer buf)
 {
     IoBuffer tmp = null;
     lock (buf)
     {
         buf.Flip();
         tmp = buf.Duplicate();
         buf.Clear();
     }
     Debug.WriteLine("Flushing buffer: " + tmp);
     nextFilter.FilterWrite(session, new DefaultWriteRequest(tmp));
 }