Deprecation Guide for Copyable.frozenCopy

Just as the Freezable mixin is deprecated in favor of functionality in core JavaScript, the frozenCopy method of the Copyable mixin is also deprecated in favor of Object.freeze().

Replace the following code:

const Obj = Ember.Object.extend(Freezable, Copyable, {
  copy() {
    return Obj.create();
  }
});

const frozenCopy = Obj.create().frozenCopy();
frozenCopy.isFrozen(); // => true
frozenCopy.set('foo', 'baz'); // => throws TypeError

with:

const a = Ember.Object.create();
Object.isFrozen(a); // => false
Object.freeze(a);
Object.isFrozen(a); // => true
a.set('foo', 'baz'); // => throws TypeError