title: CoreData configurations
body: <p>Let's say that I have 20 entities in my model at all. I need to separate these entities into 2 real storages. According to docs I have to setup two different(besides <code>Default</code>) configurations and use them later like:</p>
  
  <pre><code>self.persistentStore = try self.storeCoordinator.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: configurationName, at: url, options: nil)
  </code></pre>
  
  <p>No errors, warnings or something suspicious until I check the underlying sqlite storage — real database has <em>all</em> 20 entities! What I'm doing wrong? or what I misunderstand? </p>
  
  <p>Thanks in advance.</p>