code: function tryAddVideoBid(auctionInstance, bidResponse, bidRequests, afterBidAdded) {
    let addBid = true;
  
    const bidderRequest = getBidRequest(bidResponse.requestId, [bidRequests]);
    const videoMediaType =
    bidderRequest && deepAccess(bidderRequest, 'mediaTypes.video');
    const context = videoMediaType && deepAccess(videoMediaType, 'context');
  
    if (config.getConfig('cache.url') && context !== OUTSTREAM) {
      if (!bidResponse.videoCacheKey) {
        addBid = false;
        callPrebidCache(auctionInstance, bidResponse, afterBidAdded, bidderRequest);
      } else if (!bidResponse.vastUrl) {
        utils.logError('videoCacheKey specified but not required vastUrl for video bid');
        addBid = false;
      }
    }
    if (addBid) {
      addBidToAuction(auctionInstance, bidResponse);
      afterBidAdded();
    }
  }
docs: Video bids may fail if the cache is down, or there's trouble on the network.