src/vs/workbench/services/extensions/common/rpcProtocol.ts/MessageIO/_serializeReplyOKVSBuffer
class MessageIO:	private static _serializeReplyOKVSBuffer(req: number, res: VSBuffer): VSBuffer {
		let len = 0;
		len += MessageBuffer.sizeVSBuffer(res);

		let result = MessageBuffer.alloc(MessageType.ReplyOKVSBuffer, req, len);
		result.writeVSBuffer(res);
		return result.buffer;
	}