title: Subclassing NSManagedObject with swift 3 and Xcode 8 beta
body: <p>I've began to try use Core data with swift 3 and Xcode 8 beta. When I try to generate NSManagedObject subclasses from core data model and Create NSManagedObject subclass… option in Editor menu, Xcode 8 beta generates three files one of them is <strong>_COREDATA_DATAMODELNAME_</strong>+CoreDataModel.swift with the following content:</p>
  
  <pre><code>import Foundation
  import CoreData
  
  ___COREDATA_DATAMODEL_MANAGEDOBJECTCLASSES_IMPLEMENTATIONS___
  </code></pre>
  
  <p>In addition, the content of this file shows two warnings:</p>
  
  <pre><code>Expressions are not allowed at the top level.
  Use of unresolved identifier '___COREDATA_DATAMODEL_MANAGEDOBJECTCLASSES_IMPLEMENTATIONS___'
  </code></pre>
  
  <p>Has anyones faced the same issue? Which is the meaning of this new file?</p>
  
  <p>Thanks</p>