src/vs/platform/userDataSync/common/abstractSynchronizer.ts/AbstractSynchroniser/discard
class AbstractSynchroniser:	async discard(resource: URI): Promise<ISyncResourcePreview | null> {
		await this.updateSyncResourcePreview(resource, async (resourcePreview) => {
			const mergeResult = await this.getMergeResult(resourcePreview, CancellationToken.None);
			await this.fileService.writeFile(resourcePreview.previewResource, VSBuffer.fromString(mergeResult.content || ''));
			resourcePreview.acceptResult = undefined;
			resourcePreview.mergeState = MergeState.Preview;
			resourcePreview.localChange = mergeResult.localChange;
			resourcePreview.remoteChange = mergeResult.remoteChange;
			return resourcePreview;
		});
		return this.syncPreviewPromise;
	}