code: function replaceOldHashForNewInChunkFiles(chunk, assets, oldHashToNewHashMap) {
      chunk.files.forEach(file => {
          Object.keys(oldHashToNewHashMap).forEach(oldHash => {
              const newHash = oldHashToNewHashMap[oldHash];
              replaceStringInAsset(assets[file], oldHash, newHash);
          });
      });
  }
docs: Replaces old hashes for new hashes in chunk files.
  
  This function iterates through file contents and replaces all the ocurrences of old hashes
  for new ones. We assume hashes are unique enough, so that we don't accidentally hit a
  collision and replace existing data.