class ActiveStorage::Service::DiskService

def download(key, &block)
  if block_given?
    instrument :streaming_download, key: key do
      stream key, &block
    end
  else
    instrument :download, key: key do
      File.binread path_for(key)
    rescue Errno::ENOENT
      raise ActiveStorage::FileNotFoundError
    end
  end
end