* @param cause the cause of the decoding failure.
* @return a valid content chunk indicating failure.
*/
private MemcacheContent invalidChunk(Exception cause) {
state = State.BAD_MESSAGE;
MemcacheContent chunk = new DefaultLastMemcacheContent(Unpooled.EMPTY_BUFFER);
chunk.setDecoderResult(DecoderResult.failure(cause));
return chunk;
}