def rails_asset_id(path)
      asset_id = ENV["RAILS_ASSET_ID"]
      return asset_id if asset_id
      File.exists?(path) ? File.mtime(path).to_i.to_s : ''
    end
def rails_asset_id(path)
      asset_id = ENV["RAILS_ASSET_ID"]
      return asset_id if asset_id
      File.exists?(path) ? File.mtime(path).to_i.to_s : ''
    end
Similar to the AssetTagHelper's method of the same name, this will
 determine the correct asset id for a file.