dispatch(event) {
    switch (event.method) {
      case 'Network.requestWillBeSent': return this.onRequestWillBeSent(event);
      case 'Network.requestServedFromCache': return this.onRequestServedFromCache(event);
      case 'Network.responseReceived': return this.onResponseReceived(event);
      case 'Network.responseReceivedExtraInfo': return this.onResponseReceivedExtraInfo(event);
      case 'Network.dataReceived': return this.onDataReceived(event);
      case 'Network.loadingFinished': return this.onLoadingFinished(event);
      case 'Network.loadingFailed': return this.onLoadingFailed(event);
      case 'Network.resourceChangedPriority': return this.onResourceChangedPriority(event);
      default: return;
    }
  }
Routes network events to their handlers, so we can construct networkRecords
@param {LH.Protocol.RawEventMessage} event