js/libs/ember-1.5.1.js
function() {
    if (get(this, 'isFrozen')) throw new Ember.Error(Ember.FROZEN_ERROR);
    var obj = this.length > 0 ? this[this.length-1] : null;
    this.remove(obj);
    return obj;
  }
function() {
    if (get(this, 'isFrozen')) throw new Ember.Error(Ember.FROZEN_ERROR);
    var obj = this.length > 0 ? this[this.length-1] : null;
    this.remove(obj);
    return obj;
  }
Removes the last element from the set and returns it, or `null` if it's empty.

```javascript
var colors = new Ember.Set(["green", "blue"]);
colors.pop();  // "blue"
colors.pop();  // "green"
colors.pop();  // null
```

@method pop
@return {Object} The removed object from the set or null.