# File lib/rack/showstatus.rb, line 19
19:     def call(env)
20:       status, headers, body = @app.call(env)
21:       headers = Utils::HeaderHash.new(headers)
22:       empty = headers['Content-Length'].to_i <= 0
23: 
24:       # client or server error, or explicit message
25:       if (status.to_i >= 400 && empty) || env["rack.showstatus.detail"]
26:         req = Rack::Request.new(env)
27:         message = Rack::Utils::HTTP_STATUS_CODES[status.to_i] || status.to_s
28:         detail = env["rack.showstatus.detail"] || message
29:         body = @template.result(binding)
30:         size = Rack::Utils.bytesize(body)
31:         [status, headers.merge("Content-Type" => "text/html", "Content-Length" => size.to_s), [body]]
32:       else
33:         [status, headers, body]
34:       end
35:     end