src/vs/base/common/buffer.ts/VSBuffer/concat
class VSBuffer:	static concat(buffers: VSBuffer[], totalLength?: number): VSBuffer {
		if (typeof totalLength === 'undefined') {
			totalLength = 0;
			for (let i = 0, len = buffers.length; i < len; i++) {
				totalLength += buffers[i].byteLength;
			}
		}

		const ret = VSBuffer.alloc(totalLength);
		let offset = 0;
		for (let i = 0, len = buffers.length; i < len; i++) {
			const element = buffers[i];
			ret.set(element, offset);
			offset += element.byteLength;
		}

		return ret;
	}