docs: public V put (K putKey, V putValue) {
          V oldValue = this.store.put(putKey, putValue);
  
          if ( oldValue == null ) {
              this.notificationExecutor.firePutNotification(this.listeners.iterator(), putKey, putValue);
          } else {
              this.notificationExecutor.fireReplaceNotification(this.listeners.iterator(), putKey, oldValue, putValue);
          }
  
          return  oldValue;
      }