code: function WSPool(bus, options) {
    events.EventEmitter.call(this);
    this.setMaxListeners(0);
    this.bus = bus;
    this.logger = bus.logger.withTag(bus.id+':wspool');
    this.closed = false;
    this.pool = {};
    this.notificationChannels = {};
  
    this.options = options || {};
    this.options.secret = this.options.secret || 'notsosecret';
  
    if (!this.options.poolSize || this.options.poolSize <= 0) {
      this.options.poolSize = 10;
    }
  
    this.options.replaceDelay = this.options.replaceDelay || 5000;
    this.options.urls = this.options.urls || [];
  
    this._setupPool();
  }
docs: A pool of websockets that keeps a minimum of open websockets to a list of bus federation servers
  @param bus the bus owning this pool
  @param options additional options
  @constructor