docs: function Limitation(options) {
      events.EventEmitter(this);
      this._options = options = options || {};
      if (options.interval === undefined) {
          options.interval = 10000;
      }
  
      // Local counters. Contain objects with `value` and `limits` properties.
      this._counters = {};
      this._blocks = {};
  
      this._end = false;
      this._globalUpdatesTimeout = null;
  
      if (!options.seeds || !options.seeds.length) {
          // Single-node operation
          this._store = new MemoryBackend(options);
      } else if (options.seeds && options.seeds.length) {
          this._store = new KadBackend(options);
      }
  }