src/vs/editor/contrib/codelens/codeLensCache.ts/CodeLensCache/constructor
class CodeLensCache:	constructor(@IStorageService storageService: IStorageService) {

		// remove old data
		const oldkey = 'codelens/cache';
		runWhenIdle(() => storageService.remove(oldkey, StorageScope.WORKSPACE));

		// restore lens data on start
		const key = 'codelens/cache2';
		const raw = storageService.get(key, StorageScope.WORKSPACE, '{}');
		this._deserialize(raw);

		// store lens data on shutdown
		once(storageService.onWillSaveState)(e => {
			if (e.reason === WillSaveStateReason.SHUTDOWN) {
				storageService.store(key, this._serialize(), StorageScope.WORKSPACE, StorageTarget.MACHINE);
			}
		});
	}