# File lib/rack/static.rb, line 83
    def initialize(app, options={})
      @app = app
      @urls = options[:urls] || ["/favicon.ico"]
      @index = options[:index]
      root = options[:root] || Dir.pwd

      # HTTP Headers
      @header_rules = options[:header_rules] || []
      # Allow for legacy :cache_control option while prioritizing global header_rules setting
      @header_rules.insert(0, [:all, {'Cache-Control' => options[:cache_control]}]) if options[:cache_control]
      @headers = {}

      @file_server = Rack::File.new(root, @headers)
    end