How to create copy in Ember.js

In Ember.js, how can I create a copy of an array I get from Ember.computed.oneWay("arrayName") ?

I tried:

export default Ember.Component.extend({
    original : Ember.computed.oneWay("item.things"),
    newCopy: Ember.copy(this.get("original"), true)
})

I want newCopy to be the array of original so when I modify it, the item.things array will not be altered.