src/vs/workbench/services/extensions/common/rpcProtocol.ts/MessageBuffer/alloc
class MessageBuffer:	public static alloc(type: MessageType, req: number, messageSize: number): MessageBuffer {
		let result = new MessageBuffer(VSBuffer.alloc(messageSize + 1 /* type */ + 4 /* req */), 0);
		result.writeUInt8(type);
		result.writeUInt32(req);
		return result;
	}