src/vs/workbench/contrib/debug/common/debugStorage.ts/DebugStorage/storeWatchExpressions
class DebugStorage:	storeWatchExpressions(watchExpressions: (IExpression & IEvaluate)[]): void {
		if (watchExpressions.length) {
			this.storageService.store(DEBUG_WATCH_EXPRESSIONS_KEY, JSON.stringify(watchExpressions.map(we => ({ name: we.name, id: we.getId() }))), StorageScope.WORKSPACE, StorageTarget.USER);
		} else {
			this.storageService.remove(DEBUG_WATCH_EXPRESSIONS_KEY, StorageScope.WORKSPACE);
		}
	}