global

def call(path, headers)
  fetcher.downloader.fetch(fetcher.fetch_uri + path, headers)
rescue NetworkDownError => e
  raise unless Bundler.feature_flag.allow_offline_install? && headers["If-None-Match"]
  ui.warn "Using the cached data for the new index because of a network error: #{e}"
  Gem::Net::HTTPNotModified.new(nil, nil, nil)
end