     // MARK: - MustangDocument internal
 
     /*==========================================================================*/
-    private static let classInitialized: Bool = {
-        
-        let usagePageDescriptor = NSSortDescriptor( key: MustangDocument.defaultUsagePageTableSortKey, ascending: true, selector: #selector(NSNumber.compare(_:)) )
+    private static let classInitialization: Void = {
+        
+        let defaultUsagePageTableSortKey = "usagePage"
+        let defaultUsageTableSortKey = "usage"
+        let usagePageTableSortDescriptorKey = "UsagePageTableSortDescriptors"
+        let usageTableSortDescriptorKey = "UsageTableSortDescriptors"
+        
+        let usagePageDescriptor = NSSortDescriptor( key: defaultUsagePageTableSortKey, ascending: true, selector: #selector(NSNumber.compare(_:)) )
         let usagePageData = NSKeyedArchiver.archivedData( withRootObject: [usagePageDescriptor] )
         
-        let usageDescriptor = NSSortDescriptor( key: MustangDocument.defaultUsageTableSortKey, ascending: true, selector: #selector(NSNumber.compare(_:)) )
+        let usageDescriptor = NSSortDescriptor( key: defaultUsageTableSortKey, ascending: true, selector: #selector(NSNumber.compare(_:)) )
         let usageData = NSKeyedArchiver.archivedData( withRootObject: [usageDescriptor] )
         
         let defaultDict = [
-            MustangDocument.usagePageTableSortDescriptorKey : usagePageData,
-            MustangDocument.usageTableSortDescriptorKey : usageData,
+            usagePageTableSortDescriptorKey : usagePageData,
+            usageTableSortDescriptorKey : usageData,
         ]
         
         UserDefaults.standard.register( defaults: defaultDict )
-        
-        return true
     }()
     
     /*==========================================================================*/

        
        super.init()
        
        _ = MustangDocument.classInitialized
        
        let persistentStoreCoordinator = self.managedObjectContext?.persistentStoreCoordinator
        let managedObjectContext = NSManagedObjectContext( concurrencyType: .mainQueueConcurrencyType )


class MustangDocument: NSPersistentDocument {
    
    private static let collectionTypeNames = [ "None", "Application", "NamedArray", "Logical", "Physical" ]
    
    fileprivate static let sqliteOptions = [
