3 Contain async insanity so that the dark pony lord doesn't eat souls
6 post](http://blog.izs.me/post/59142742143/designing-apis-for-asynchrony).
10 Pass a callback to `dezalgo` and it will ensure that it is *always*
11 called in a future tick, and never in this tick.
14 var dz = require('dezalgo')
17 function maybeSync(arg, cb) {
20 // this will actually defer to nextTick
21 if (cache[arg]) cb(null, cache[arg])
23 fs.readFile(arg, function (er, data) {
24 // since this is *already* defered, it will call immediately
26 cb(null, cache[arg] = data)