src/vs/platform/userDataSync/common/snippetsSync.ts/SnippetsSynchroniser/updateLocalBackup
class SnippetsSynchroniser:	private async updateLocalBackup(resourcePreviews: IFileResourcePreview[]): Promise<void> {
		const local: IStringDictionary<IFileContent> = {};
		for (const resourcePreview of resourcePreviews) {
			if (resourcePreview.fileContent) {
				local[this.extUri.basename(resourcePreview.localResource!)] = resourcePreview.fileContent;
			}
		}
		await this.backupLocal(JSON.stringify(this.toSnippetsContents(local)));
	}