code: function MemoryBackend(options) {
      this._options = options || {};
      assert(this._options.interval, 'options.interval is required');
      if (!this._options.minValue) {
          this._options.minValue = 0.1;
      }
  
      this._counters = {};
      // Exponential decay with factor 2, thrice per interval for better
      // smoothness, using the cubic root of 2).
      this._decayFactor = Math.pow(2, 1/3);
  
      // Start the periodic decay process.
      var self = this;
      this._decayCountersInterval = setInterval(function() {
          self._decayCounters();
      }, self._options.interval / 3);
  }
docs: Creates an in-memory kad storage adapter
  @constructor