Interface Memento

packages/common/infra/src/storage/memento.ts:8–15

 * A memento represents a storage utility. It can store and retrieve values, and observe changes.
 */
export interface Memento {
  get<T>(key: string): T | undefined;
  watch<T>(key: string): Observable<T | undefined>;
  set<T>(key: string, value: T | undefined): void;
  del(key: string): void;
  clear(): void;
  keys(): string[];
}

/**
 * A simple implementation of Memento. Used for testing.