call

# File actionpack/lib/action_controller/vendor/rack-1.0/rack/showstatus.rb, line 19
    def call(env)
      status, headers, body = @app.call(env)
      headers = Utils::HeaderHash.new(headers)
      empty = headers['Content-Length'].to_i <= 0

      # client or server error, or explicit message
      if (status.to_i >= 400 && empty) || env["rack.showstatus.detail"]
        req = Rack::Request.new(env)
        message = Rack::Utils::HTTP_STATUS_CODES[status.to_i] || status.to_s
        detail = env["rack.showstatus.detail"] || message
        body = @template.result(binding)
        size = Rack::Utils.bytesize(body)
        [status, headers.merge("Content-Type" => "text/html", "Content-Length" => size.to_s), [body]]
      else
        [status, headers, body]
      end
    end