    # File lib/rack/handler/webrick.rb, line 25
          def self.run(app, options={})
            environment  = ENV['RACK_ENV'] || 'development'
            default_host = environment == 'development' ? 'localhost' : '0.0.0.0'

            options[:BindAddress] = options.delete(:Host) || default_host
            options[:Port] ||= 8080
            options[:OutputBufferSize] = 5
            @server = ::WEBrick::HTTPServer.new(options)
            @server.mount "/", Rack::Handler::WEBrick, app
            yield @server  if block_given?
            @server.start
          end