code: private static BinaryMemcacheRequest handleObserveRequest(final ChannelHandlerContext ctx,
          final ObserveRequest msg) {
          String key = msg.key();
          short keyLength = (short) msg.keyBytes().length;
          ByteBuf content = ctx.alloc().buffer();
          content.writeShort(msg.partition());
          content.writeShort(keyLength);
          content.writeBytes(key.getBytes(CHARSET));
  
          BinaryMemcacheRequest request = new DefaultFullBinaryMemcacheRequest(EMPTY_BYTES, Unpooled.EMPTY_BUFFER, content);
          request.setOpcode(OP_OBSERVE);
          request.setTotalBodyLength(content.readableBytes());
          return request;
      }
docs: Encodes a {@link ObserveRequest} into its lower level representation.
  
  @return a ready {@link BinaryMemcacheRequest}.