src/vs/workbench/contrib/snippets/browser/snippetsService.ts/SnippetsService/_initWorkspaceFolderSnippets
class SnippetsService:	private async _initWorkspaceFolderSnippets(workspace: IWorkspace, bucket: DisposableStore): Promise<any> {
		const promises = workspace.folders.map(async folder => {
			const snippetFolder = folder.toResource('.vscode');
			const value = await this._fileService.exists(snippetFolder);
			if (value) {
				this._initFolderSnippets(SnippetSource.Workspace, snippetFolder, bucket);
			} else {
				// watch
				bucket.add(this._fileService.onDidFilesChange(e => {
					if (e.contains(snippetFolder, FileChangeType.ADDED)) {
						this._initFolderSnippets(SnippetSource.Workspace, snippetFolder, bucket);
					}
				}));
			}
		});
		await Promise.all(promises);
	}