RxJS Observer outside of Observable.create

RxJS-simple-create

var Rx = require('rxjs');
var source;

var timeline = Rx.Observable.create(function(observer){
  var to;
  var last = null;
  source = observer;

  return function() {
    console.log('observer ended ');
  };
});

setTimeout(function(){
  source.next('First data');
  setTimeout(function(){
    source.next('Second data');
    source.complete();
  }, 500);
}, 100);

timeline.subscribe(function(d){
  console.log('subscribe '+d);
});