Obj-c method with nullable return value not properly converting to swift

I have a problem where the following OBJ-C method will not translate to Swift with optional return value:

- (nullable id)executeRequest:(ServerRequest *)request returningResponse:(__nullable NSURLResponse **__nullable)responseRef errorRef:(NSError **)errorRef

When trying to override that method in a swift class it translates to this:

override func executeRequest(request: ServerRequest, returningResponse responseRef: AutoreleasingUnsafeMutablePointer<NSURLResponse?>) throws -> AnyObject

Note that the return value is AnyObject instead of AnyObject?

What am I doing wrong here? I'm using X-Code 7 Beta 3

via Chebli Mohamed