Non of the code runs in chapter 11 (Can't set headers after they are sent)

还没有人认领这个 Issue。

If you try running any code in chapter 11 you get the same error "Can't set headers after they are sent"

Express 3.0.0beta7
CoffeeScript version 1.3.3
Node v0.8.2

http.js:644
throw new Error('Can\'t set headers after they are sent.');
^
Error: Can't set headers after they are sent.
at ServerResponse.OutgoingMessage.setHeader (http.js:644:11)
at ServerResponse.res.setHeader (/Users/work/todo/node_modules/express/node_modules/connect/lib/patch.js:62:20)
at ServerResponse.res.header (/Users/work/todo/node_modules/express/lib/response.js:280:8)
at ServerResponse.res.json (/Users/work/todo/node_modules/express/lib/response.js:135:8)
at Create.global.Responder.Responder.complete (/Users/work/todo/src/controllers/responders/responder.js:27:25)
at Promise.__bind (/Users/work/todo/src/controllers/responders/responder.js:3:63)
at Promise.addBack (/Users/work/todo/node_modules/mongoose/lib/promise.js:120:8)
at Promise.EventEmitter.emit (events.js:88:17)
at Promise.emit (/Users/work/todo/node_modules/mongoose/lib/promise.js:59:38)
at Promise.complete (/Users/work/todo/node_modules/mongoose/lib/promise.js:70:20)

首先使用列出的 CoffeeScript、Express 和 Node 版本运行第 11 章中的一个示例，然后将报告的失败追踪到 src/controllers/responders/responder.js。将第 11 章的其他示例进行比较，以确定它们是否到达相同的 responder path；完成的标准是章节示例能够运行且不会出现报告的 headers error。

由索引模型根据 Issue 内容生成。