class Bundler::Fetcher::CompactIndex

def bundle_worker(func = nil)
  @bundle_worker ||= begin
    worker_name = "Compact Index (#{display_uri.host})"
    Bundler::Worker.new(Bundler.settings.processor_count, worker_name, func)
  end
  @bundle_worker.tap do |worker|
    worker.instance_variable_set(:@func, func) if func
  end
end