gistfile1.js

Obj.prototype.doSeries(cb) {
 var state = {}
 async.series([
  this.doA.bind(this, state),
  this.doB.bind(this, state),
  this.doC.bind(this, state),
 ], function(err, result) {
   cb(err, result);
   // do i need to state = null here?
   // will that even help?
 });
}

// and then do a bunch of 
someObj.doSeries(function(err, res){});