The idea for protocol based storage/store system for Backbone.

BackBone.Stream.js

// Protocol
function BackBoneStreamType(stream){
  this.stream = stream; // Ex... XMLHTTP, Local/Session Storage
}

BackBoneStreamType.prototype.recieve = function(callback){}
BackBoneStreamType.prototype.send = function(callback){}
BackBoneStreamType.prototype.close = function(callback){}


// HTTP Stream and confirming BackBoneStreamType
function HTTPStream(){
  this.stream = new XMLHTTPRequest();
}
util.inherits(HTTPStream, BackBoneStreamType);

HTTPStream.prototype.send = function(){
  this.stream.brabrabra();
};

// Broswer storage
function BrowserStorageStream(stream){
  this.stream = stream;
}
util.inherits(BrowserStorageStream, BackBoneStreamType);

BrowserStorageStream.prototype.send = function(data){
  this.stream.brabrabra();
};


// Usage
const model = Backbone.Model.extend({
  stream: new HTTPStream() or new BrowserStorageStream(localStorage)
})

model.sync() // http stream works in the internal sync method.