Open Radar

 
Summary:
When trying to generate extensions for entities in a Core Data Model, Xcode generates both a subclass and an extension.

Steps to Reproduce:
1) Create a new single view project that uses Core Data
2) Add a simple entity, say a `Person` with a `firstName`, `lastName`, and `age`.
3) Select the Core Data model file
4) In the Data Model Inspector panel under the "Class" section, select "Category/Extension" for the Codegen option.
5) Verify in the File Inspector panel the Language in the "Code Generation" section is "Swift"
6) Editor > Create NSManagedObject Subclass ...
7) Follow the steps to generate the code

Expected Results:
One file per entity should be generated (EntityName+CoreDataProperties.swift).

*Note: This behavior is described here: https://developer.apple.com/library/prerelease/content/releasenotes/General/WhatNewCoreData2016/ReleaseNotes.html 

Actual Results:
Two files are generated.

1) EntityName+CoreDataProperties.swift
2) EntityName+CoreDataClass.swift

*Note: This behavior is what I would expect for the "Class Definition" option.

Version:
macOS 10.12 (16A323)
Xcode 8.0 (8A218a)
Swift 3

Notes:
I also tried using the "Class Definition" option and it generates the same files as the "Category/Extension" option.