js/libs/ember-1.5.1.js
function(obj) {
    Ember.assert('Must pass a valid object to Ember.Binding.connect()', !!obj);

    var fromPath = this._from, toPath = this._to;
    Ember.trySet(obj, toPath, getWithGlobals(obj, fromPath));

    // add an observer on the object to be notified when the binding should be updated
    Ember.addObserver(obj, fromPath, this, this.fromDidChange);

    // if the binding is a two-way binding, also set up an observer on the target
    if (!this._oneWay) { Ember.addObserver(obj, toPath, this, this.toDidChange); }

    this._readyToSync = true;

    return this;
  }
function(obj) {
    Ember.assert('Must pass a valid object to Ember.Binding.connect()', !!obj);

    var fromPath = this._from, toPath = this._to;
    Ember.trySet(obj, toPath, getWithGlobals(obj, fromPath));

    // add an observer on the object to be notified when the binding should be updated
    Ember.addObserver(obj, fromPath, this, this.fromDidChange);

    // if the binding is a two-way binding, also set up an observer on the target
    if (!this._oneWay) { Ember.addObserver(obj, toPath, this, this.toDidChange); }

    this._readyToSync = true;

    return this;
  }
.......................................................... CONNECT AND SYNC  
Attempts to connect this binding instance so that it can receive and relay
changes. This method will raise an exception if you have not set the
from/to properties yet.

@method connect
@param {Object} obj The root object for this binding.
@return {Ember.Binding} `this`