gistfile1.txt

{
    inflight: undefined
    , fetch: function() {
         if(this.inflight && this.inflight.then) {
           return this.inflight.then(fetch.bind(this))
         }
         return this.inflight = Promise.resolve().then(function() { 
             //cant remember what jquery xhr api is ...i think 'done' is the thing here.
             return this.save().done(function(res){
                 this.inflight = undefined
                 return res
             })
         })
    }
}