src/vs/base/parts/ipc/common/ipc.net.ts/ProtocolWriter/_bufferAdd
class ProtocolWriter:	private _bufferAdd(head: VSBuffer, body: VSBuffer): boolean {
		const wasEmpty = this._totalLength === 0;
		this._data.push(head, body);
		this._totalLength += head.byteLength + body.byteLength;
		return wasEmpty;
	}