code: @Override
      public void filterWrite(NextFilter nextFilter, IoSession session,
              WriteRequest writeRequest) throws Exception {
  
          Object data = writeRequest.getMessage();
  
          if (data instanceof IoBuffer) {
              write(session, (IoBuffer) data);
          } else {
              throw new IllegalArgumentException(
                      "This filter should only buffer IoBuffer objects");
          }
      }
docs: {@inheritDoc}
  
  @throws Exception if <code>writeRequest.message</code> isn't an
  {@link IoBuffer} instance.